Probably for the best; any of Menzoberranzan's Great Houses were so far above Ilphyl's pay grade even if they hadn't completely rejected their own birth family (which, hopefully, still assumed Ilphyl was dead).

"In passing." Ilphyl was a lot more comfortable eavesdropping around Waterdeep, where 'unusual person' was a high bar. Especially given Skullport beneath the city meant that there was access to the Underdark. Ilphyl was more likely to be backup when someone else was gathering information.

"I'm Ilphyl." They could probably claim the druid circle that had finished their training, but they hadn't been back there in a while.