Wow factors for a 90mm.....hmmm. At this time of year, minus a Moon in the sky, you could try Omega Centauri (globular cluster), the Jewel Box (open cluster), Alpha Centauri (triple star...although you'll only see the two main stars), Eta Carina Nebula, M6 and M7 in Scorpio (open clusters), Albireo (double star in Cygnus), Epsilon1,2 Lyrae (the famous double-double star in Lyra), Ring Nebula (M57 in Lyra), and there's a raft of others that could be mentioned.
You could even dazzle here with some statistics. Say you had Antares in your eyepiece...you could say that if the Sun was the size of a marble (1cm) then the star you're looking at would be a ball 7 metres across. Better still, tell her if she wanted to drive her car from one side of Antares to the other, it would take her 1152 years to make the journey!!! (doing 100km/hr). That should boggle her brain a bit
