Alma is of two minds.
On the one hand, it's wrong, it's embarrassing, it's shameful. It goes against everything she's ever known to be true. She knows her friends will be giving her the looks of death. She knows they will talk about her behind her back, and her priest? There is no end to the 'Our Fathers' and 'Hail Marys' he'll demand.
But on the other hand, Santana is the fruit of her fruit. Brittany, though dishonest, has always been of good heart where Santana is concerned. And Maribel mentioned grandchildren.
It's between head and heart.
Alma's heart wins.