How do I tell politely tell my mom and sister in law no?

K

So I just had my daughter 7 months ago. Well my now future sister in law is pregnant. My mom keeps asking me if she can use/borrow stuff. There are some things I don’t mind them using like the swing my daughter has outgrown and a few other things. But I know if they have a girl too they are going to want me to just hand over everything. I don’t want too. I’m not okay with just giving up my daughters clothes right now. We don’t plan on having another one for awhile but I can’t.

Maybe I still need time to process everything since I was just told Monday? Maybe I’m a little jealous because I would love to be pregnant again right now?