Martha took Star's hand when she offered it, privately somewhat relieved that she wouldn't have to completely guess what the girl might like to eat. At least in the kitchen together they might be able to work something out.
She watched as Star spelled out the name before she shook her head. "Sorry, I don't know a Kyle. But I don't know everyone here so that doesn't necessarily mean anything."
It wasn't a lie as such, Martha really didn't know everyone at the apartment, so there could have been a Kyle around, even if she suspected the one Star was looking for was still back wherever they'd come from. Still, she didn't want her freaking out and running away, so keeping it vague, she hoped, would work.