Well, that's why I'll stand behind you and look threatening!! They'll be too scared not to answer you!

[Of course, Undyne's definitely following - at this point it's all but been cemented in her head that this is an Actual Child from her world, human or not, and she's never been too good at letting kids go off and potentially get hurt.
She'd even admit it herself!! Because what hero of the people would let kids go get hurt??]

... We should probably ask'em where we are, first. It's obviously it's the surface, but where on the surface?