Are the gatherings at your parents' house generally louder than the ones you host? It could just be that she's overstimulated by being in a new place and around a large number of people, especially if those people are interactive with her. Next time you're at a gathering at your parents, see if you can find a quiet room and maybe slowly introduce her back to the party or wait til she falls asleep and then go back
At this age babies definitely get overstimulated in new environments! It’s normal, but definitely exhausting when you’re trying to enjoy the party. I find that taking breaks helps, finding a more calming space for baby to regulate for a bit & babywearing for comfort.
My daughter doesn't like noise she likes calm no chaos!!! Our house environment is very calm and less noisy we are noisy but we don't make a racket but when we go over to his aunts house holy shit she screams!!! Sooo I feel you
My LO is the opposite. She’s better in groups and seems to fuss more at home and in the stroller. It gives me anxiety to take her on stroller walks, which is a bummer bc I was really looking forward to them. They all have their own personalities!