How can i tell her without seeming rude ?

My grandfathers wife has a pet opossum and I have no problem with that I'm just afraid to touch it or let it scratch/bite me because it has bit her several times I'm 27 weeks pregnant she continuously tries to get me to hold it etc. I'm not sure how to tell her that I don't want to I know this it sounds silly but she really adores it and I'm afraid I'll hurt her feelings 🤦🏼 its not just her pet though I won't go around cats either I'm just extremely paranoid about everything right now.