Either way works, Caitlin.  While they're both nurses at the same hospital, there are literally dozens of nurses that work there and on different floors, wings, or even buildings.  She could know the name Lawson, but maybe she doesn't put it together right away.  Lawson doesn't seem like it's that unique of a last name.  She could have also known the kids when they were younger, but they're teenagers now and teenagers are notorious for not wanting to go to their parent's functions, so she may not recognize them.<br/><br/>It's also very plausible that while Caitlin knew Nancy in a work setting, she didn't know her beyond.  She may've even recognized David (her husband), because Caitlin saw him more often, but not the kids.  Especially if they show up with another set of adults.<br/><br/>Eventually putting 1+1 together will be fun, but if you don't want Caitlin to immediately jump on it that's quite alright.  In fact, if she doesn't that would seem more realistic than if she does.  I think most of the survivors would be concentrating on a number of other things and not quite realize they've got a connection to one another, until they find a bit of relative safety or have time to reflect and grieve?<br/><br/>Just my thoughts on the subject.  If you're good with your character knowing their mom, then I figure we can PM each other and talk about the details there.