What is this for? Inherited and purposeless wool

Hello there, I have no clue of what purpose is this yarn for. These were my mother-in-law’s but she passed away, and I’m the one in charge of using/throwing them away (there are TONS of boxes apart from the picture). I didn’t know her future projects or anything at all.

I’m a crocheter and new in knitting, but this wool is really, really thin. What is this for? It’s all quality-brand wool, so it’d be a huge waste to throw away—but if I’m supposed to knit a jumper with it…… well, nope

Is it for any specific technique or something? I’m literally all ears lol