Considering that my waifu is Marisa, I don't think I need to worry about her physical state. She's a tough girl, a confident woman and a magically strong person. She faced a lot of enemies and won, and practically lives in a deadly forest, handling chemicals that could kill the average person slowly in experiments that can potentially involve life-threatening forces or worse.
But about her mental state, I dunno. It makes me wonder and worry, she's been practicing and researching her stuff for a long time, in a solitary state. While she ain't a hermit, that's another problem. Her pride doesn't allow for her to show any sign of helplessness or weakness and she's afraid, I think, of being pitied and being seen as trying hard. She doesn't seem to have a good relation with her father and her personality can put some people off her. Moreso, she claimed to be insane when she stared at the fake moon and didn't go lunatic.
Yeah, I worry about her mental well-being.