When I say real problems, I mean things like abuse, disability, chronic illness, or social strife (war, persecution, etc).

Funny you mention my mom not understanding. I think she's just starting to, though damn did she miss a lot, apparently.

My mom has bipolar II, and has recently been slipping back into a depressive episode. The other night she told me so, and asked if I understood what was happening. I said yes. Apparently, she didn't realize until now just how cognizant I was of something being wrong with her, and how much her mood swings and episodes scared me at times. By the time I was 12, I was prepared to come home and find her dead, or would worry that she was late picking me up because she had killed herself. Crazy, I know, but to me it seemed a perfectly reasonable possibility from someone who would start randomly talking about suicide sometimes.

My mom now sees me as incredibly mature for witnessing her for having coped with her disorder at such a young age. Somehow this segued in to her declaring my own depression is definitely real, and it's not faking. At the same time, like I mentioned in my OP, she'll call my SI melodramatic and such. So I don't know how much she understands of me.