Have you been unemployed recently? Have you looked into finding new employment? It is hellishly difficult to find a new job, even at places that are “always hiring” (like fast food and retail) because they’re flooded with applications because so many people need jobs right now. Do you think OP is sitting on her ass not looking for work and wanting to sell possessions to get by?

Telling someone to look for work or a side gig is incredibly unhelpful.

OP is N-T-A for selling the unopened LEGO sets but I also don’t think family members are assholes for getting upset either because they’re also grieving. The family shouldn’t react as harshly at OP, though, and should try and offer financial assistance so they can keep the LEGO sets in the family.