I feel like I'm constantly under minded because I'm a "young parent"!

I hate being around my family because I feel like they don't respect me as a mother or adult! I'm 23, married and expecting my second child. It seems like no matter how grown I get my older relatives try to step on my toes. Fe, my family and I stay in an apt above my moms house so sometimes when family stops by her house they come to my house to see the baby. 
I don't really like it because they just stop by with no warning and sometimes we're sleeping, my husband may not be dressed or we just may not want company! 
Anyway today my grandmother stopped by and I was in the middle of potty training my 1yo. She walked into my bedroom uninvited while I was undressed and sat on the floor and started to play with my baby while she was on the potty. I was on the phone so I told her she could hang out with her in the living room but she needed to take the potty so she could sit back down on it to pee. Instead she took my daughter into my moms Space (my baby is fully naked btw). Once I realized, I told my grandma that my baby isn't allowed to be naked in front of people. I'm not saying anyone would hurt her but I think it's inappropriate. I don't know who my mom has In her space and I have a brother and I'm not comfortable with anyone being around my daughter while she isn't clothed. So when I went to grab her my grandma told me it was stupid and it shouldn't be a problem. It's my kid! All that matters is what me and my husband feel! Right?! Wtf