My GF Only Masturbates When She's Upset

Is this a thing? She says it helps.

She lets me hug her while she's feeling herself up, bawling her eyes out on me which does turn me on somehow. I asked her what I could do to help, and she told me just staying with her was what she wanted. We always talk it out afterwards.

But seriously, does anyone else do this?

I'm bringing this up because yesterday she was really upset, I heard her when I walked inside. She called me over, yelling and sobbing (I'll keep it vague, but a member of her family wasn't doing well). I sat down with her, took my shirt off, as I do usually, and she leaned into me so I could embrace her. She was still wearing her purple puffer jacket and her face was completely soaked in tears. Both her hands were busy down below so I just held her tight while she pressed her forehead against mine and groan-sobbed.