Cindy, I'm very sorry for the loss of your Mom. You've inherited cultured freshwater pearls, ringed and baroque shape, just like you mentioned. the clasp with .925 is sterling silver. The other clasps may be rhodium plated. It's difficult to say exactly how old the pearls are as similar pearls are still available. The thread isn't stretched or worn looking.
These pearls aren't expensive, but are favored because they are all nacre and will never wear through to a bead center. So I hope you will enjoy wearing them and layer with other jewelry for fun.
Do you remember your Mom wearing them?