This would only pose a problem if you decide to have either of the younger pups' ears cropped. If she is simply playing with them and slobbering on them, there shouldn't be any harm, unless she's being a bit rough. This is right around the time they're teething, so their ears are going through a whole lot of funky phases right now anyway. The only issue I may see is that if she's being too rough with them, she could break the soft cartilage causing them to be permanently set in a funky position when they're older and the cartilage hardens. If it bothers you, then I would put a stop to it by correcting her now.
You didn't lose your girl, you just lost your turn!
"In this breed, there's no such thing as an expert! The day someone says they're an expert, they need to walk away from the dogs, because someone's going to get hurt. You should be learning something new every day." John Maynard-Circle M Kennels