Hello!! I am an ISFJ and also a mom -- in addition to growing up with a very abusive father, so I will throw in my .02 here. Well, it might be .03, but I'm gonna anyway!
I've also been through many years of counseling in order to become more healthy, so I can see both sides of the coin. I might get slammed for this, but I think it's hard for people to really know what's going on inside an ISFJ unless you have been really close to one or you are one. And we're not all the same....in terms of what function we use most (mine is Ti for example and I'm pretty sure Giggly's is Fi or Fe) or our level of healthiness or the experiences we've gone through in our lives. My sister is an ISFJ as well, but a whole other ball of wax. But, I digress.
An unhealthy ISFJ has a very low self esteem. I can tell you from growing up with a very verbally abusive father who was negative ALL the time ("You got 5 A+'s and a B??!!" Let's talk about what you did wrong to get a B!"), it kind of becomes a way of life for you. Your internal critic goes on overdrive and you constantly feel like you're not good enough. Other people tend to take advantage of you and you let them. In doing that, you reinforce your own low self esteem -- because if you were worth something, other people wouldn't take advantage of you. It's a bad cycle. I am glad I worked my way out of it. However, I STILL feel like everything that goes wrong is my fault sometimes when I'm stressed out or hormonal. That's part of an ISFJ that is part of our nature, I think. An unhealthy ISFJ is going to have a tough time setting boundaries. They aren't sure what appropriate and healthy boundaries are or how to make them. So they end up resentful, but feeling like they can't do anything about it. They can be very pessimistic. When they get feedback from other people, they tend to ignore the positive stuff and focus on the negative stuff. But they do this ALL IN THEIR HEAD. And they have exceptional memories. You could say five nice things and one bad thing to them and they will focus on the bad thing and beat themselves up with it. They can pull something out of their memory from a long time ago and continue to focus and berate themselves for it. (I'm talking about unhealthy ISFJs here, although we all have our little down times.)
Because your mom can't set healthy boundaries and she puts her family first, YOUR problems become HER problems. She feels responsible for them and for all of you and worries, etc. Although she may have seemed surprised when something good happened for you or you achieved something, it's not because she doesn't believe in your or isn't happy for you, it's because she EXPECTS the worst. That way, when things go bad, she is "prepared" in her mind. Some of these things are hard to articulate...especially to other personality types. I guarantee that she loves you more than anything (I would do ANYTHING for my kids and husband) and she does want you to be happy. Even when I was at my unhealthiest, I wanted those things.
Here are my ideas on what you can do to help. I don't know if she's thought about counseling or done it, but that might help her. However, it is not YOUR job to "fix" her. So: Make sure you tell her that you appreciate her a lot. It is important to her to feel appreciated. Tell her thank you when she does things for you. Or just for the family in general. Maybe get her a card to tell her how much you appreciate her. And maybe you don't have the emotional connection thing, but I can tell you as an ISFJ mother of two boys (one is 18 and an ENFJ - just one away from you) that my kids can't tell me enough that they love me. I took my oldest son to work today because his car is in the shop...and I grumbled about it a little bit. But he sent me a text from work later, saying how much he appreciated it...and that made all the difference for me. When I make dinner and the boys say "that was great, thank you", it means a lot to me. My oldest knows that I LOVE peanut M&M's and he brought me home some as a surprise the other day. I cherish the fact that he knows me well enough to know what I like..and that he thought of me. I honestly don't know how comfortable T's are with those kinds of things, as I'm surrounded by F's (I need more exposure to T's!)...but you are asking, so I think you are willing to do what you can.
Does she have hobbies? Show an interest in a hobby she has. We like to feel like we've helped others, so ask for her advice in situations. If you take her advice, that will be an even bigger thing for her. She will feel positive that she "helped" you. I'm also partial to hugs and physical affection.
Your mom probably has some work to do on herself, if she's willing. I have learned over the years to not let other people take advantage of me (I couldn't be resentful if I "allowed" it!), to set boundaries and be okay with saying "NO" when I needed to. When I was going through counseling and all of that, I took Prozac and then Zoloft for awhile and those helped a lot. I learned how to set boundaries so I didn't become emeshed in other people's problems. That was particularly hard with my children, but I was harming them by NOT doing that. Encourage your mom to do things for herself. We are so busy putting everyone ahead of us that we put ourselves last sometimes. Encourage her to get a manicure or have a glass of wine and read a book and let other people do things for HER for awhile. Maybe share your life with her more too -- I love it when my 14 year old son talks about his friends and his "girlfriend" and social life. It makes me feel good that he feels like he can talk to me.
I don't care what anyone else says...at the heart of us ISFJs - we are all very good and loving people with a good hearts. This last week I had lunch with a friend of mine and she told me that a friend of hers thought I didn't like her. I was very surprised...because I do in fact like her and I've never given any indication otherwise. However, because I'm reserved..and I'm not a touchy huggy person, many people don't know how I feel. Much of it goes on in our head. So other people misinterpret us. Which I know happens to other personality types too. I'm just speaking specifically from this situation.
No clue if I've helped...let me know if you have any other questions. Other people have been so kind in giving me answers to my questions and I'm happy to reciprocate!!
