Yes, these insects are used to feeding on the nectars from plants, and your girl apparently just started smelling appetizing, which attracted them in hopes of sipping nectar from the plant! Such visitors can easily pollinate her since they land on similar plants, including the males! 👆
If this was a one-time occurrence, no worries! If they visit her often - expect eggs, the butterflies will pollinate her! 👆
You can make a barrier out of mosquito netting on the side from which they usually fly and land! Butterflies usually don't fly high, they'll either land on the net or fly past it. Eventually, you'll have time to spot them nearby and chase them away before they land on your girl!
Good luck, bro! ✊😇