Help ID for a friend please

[PSCoral]

These started showing up in her tank but as I haven’t encountered these before I was of no help, I’d appreciate if anyone could tell me what these are and if they’re a problem. Thank you

 

[Reefering1]

 

[ISpeakForTheSeas]

These started showing up in her tank but as I haven’t encountered these before I was of no help, I’d appreciate if anyone could tell me what these are and if they’re a problem. Thank you

Really can't say from the pics, but possibly medusa-stage hydroids?