Kim Mulkey was an assistant and associate head coach under Hall of Famer Leon Barmore at Louisiana Tech.
Nikki Caldwell Fargas under Pat Summit
But you're right in implying being an assistant on a great HC's staff doesn't mean you'll be any good as a HC when you are put in that position
Fred Hill ( Coached Jay Wright) ?? Wrong , wrong , wrong
Fred was a successful RU mens baseball coach for 29 seasons and his record of 941–658–7 at Rutgers isn't a bad one at all
Now if you're talking Freddie Jr , that's a horse of a different color

and I say he was more into Gary Waters then a Jay Wright clone. Also was an assistant at various programs for around 20 years before hooking up with Jay.
Can't put him on Jay's coaching tree and I won't put him on Gary's
But I will admit, no matter what tree Hill JR fell out of : Judy in disguise was a failure as the RU MBB HC
Coquese started her coaching career under Muffet McGraw at ND but hasn't proved to be a winner , but had a good 4 year run at Penn St (101-31) but overall her time there ( 209-169) wasn't something that deserved a standing ovation
I'll put Fast Eddie's tree under Bob Wenzel , 128-135 at RU. who was the second HC he served under
His first assistant position was at BC on Jim O'Brien's staff
Byron Scott had a lifetime losing record so being in his tree is nothing to write home to mother about