There is tons of good riding in Northern Vermont. How many days are you riding there? If you're staying at the KT, you could check out the Jay Peak area (Montgomery and Jay has some great riding!) which is about 45min from the KT. Just accross the border there is a 18km (12mi) loop that is pretty technical in Coaticook, QC. The trails has been rebuilt in late may by the IMBA trails care crew along with ADSVM.org and bikers from Quebec. The terrain is compact and your gf might also enjoy a nice loop by using the shortcuts to avoid the more techy stuff... Again, 45min south is Millstone Hills which is pretty nice also.
I would stay away from Sleepy Hollow with your girlfriend... I found the trail to be "technical" but on the badside of the terms... meaning: No flow and useless rocks! Rocks are fun when the trail has flow... doing 2mph avoiding rocks on flat isn't my idea of fun... maybe it's just me!
Check out
www.fotwheel.og for some riding opportunity and a few maps located on their kingdom...
I should be in the area in 2 weeks... 7-9th of July... Our plan is Jericho, Millstone Hills and Waturbury.