As others have said, I think it's kind of weird that Alpha would show her face since Hilltop has already seen it. Her appearance doesn't exactly blend in with everyone in first place.
Urgency also doesn't seem to register with Maggie when her friend's only son has gone off chasing a civilization of skin-wearing crazies with the intent of doing something they won't like. Even beyond not sending a messenger, she just casually brings her stuff to her room and has a heartfelt moment before going to Rick and breaking the news. It's almost like she doesn't care very much, which doesn't feel right.
Lastly, I'm a bit confused about what the purpose is of Magna and her group at this point. It seemed they'd be a bigger deal starting out, but currently they're little more than ordinary Alexandria citizens; they get a few scenes every now and then, particularly Magna, but aren't really involved in anything. The last thing The Walking Dead needs right now is more characters who don't matter.