I think Frog Dad is holding Frog Moms hat so she probably died.
I thought it was that moment, since he was wearing suit there so I assumed it might have been after funeral. Although now that I look at it, bowtie seems to suggest something else.
So either parents devote their daughters to being Brides of Christ at babyhood, or the Convent is rather a Convent School rather than a Nunnery...
From what we've seen, the younger nuns are given an education and only have to choose whether to take the veil or not when they grow up. Spicy Nun's mom chose not to, the rest of her generation chose to. It's just that at this convent all the women wear habits vows or none.