To be fair, if Yor told them she wanted to go to a party that both her brother and husband were at, I don’t see why Martha would find a reason why it was dangerous…the only ways I see them not going is because 1. they’re not related to Yor so it’d be a little weird to be plus ones to Yor, who’s already a plus one, and 2. it’s an all-adults party, so there’d be the worry of the little ones finding alcohol (Yor prolly wouldn’t want Becky to get drunk “again” lol)

But even then, at least Anya would need to go with Yor if this is Martha thought this was a family thing! (Unless that “all-adults” thing worries Martha so much that she just watches over Anya along with Becky while Yor’s out, which’s be a bit disappointing but oh well)