You would also fit on a Bike Friday with 20" wheels. I have one I bought for touring but it's great for regular road riding as well.
Agree too with the Terry recommendation. I used to have an Isis and fit well on the 17.5" size at 5'2" with 28.5"ish inseam. You'd need the smallest size (16"). There's a gal in the club I used to be in around your height that rides that size.
Definitely agree about the MTB -- I love mine and ride it on the road for utility rides and on paved trails, but it's quite heavy compared to my road bikes.
Good luck!
Emily
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow