Did Androse really mean Umbriel when he asked about expertise on wands with a teasing wink, or Godot? If he's wandering back over to Umbriel (who's waiting in line to get a drink from the beer wagon as an excuse for hanging around and inspecting people with Arcane Sight), she will probably be rather amused by that question
Re "children", Umbriel is old enough to be Derk's mother - or grandmother, if she were human
She's quite elderly (75, although illumians live longer than humans), at an age where she's noticeably slowing down physically, although her mind is sharper than ever. Her spells help with mobility and make her less frail, but don't really disguise her age.
EDIT: Familiar's initiative is +2, but she will rarely be an independent combatant.