yeh she is too heavy for your front but its possible on the hip!
Izzy weighs around 24lb and she feels as light as a feather in hip slings - yet I couldn't carry her in the front carrier after 4 months!
I have 2 types of hip sling, a ring sling (which is good if more than one parent will use as its adjustable) and also a fleece pouch (in size for the user)
ring sling http://www.herbalbaybee.co.uk/page7.htm
pouch http://www.herbalbaybee.co.uk/page6.htm
Although I want this one - kind of the best of both worlds http://www.herbalbaybee.co.uk/page9.htm (''Suitable for newborns through to toddlers up to 35lbs (3 years +)'')
If you wanted to try one out I could lend you one?