You gotta get tough mom :) I echo the comments about letting her cry it out. A 16 month old can have lots of determination --- but that only increases --- so do it now. That's my 2 cents anyway. I let my children cry it out at 8 weeks. It took about 3 days and they have been wonderful sleepers ever since. It definitely isn't easy. There are rescources out there to help you figure out how to implement it realistically. Super Nanny does something like it. You can also look for the book Babywise --- its for infants but there is a version for older kids too. The Babywise materials can be a bit "extreme". I took parts of it and just ignored the rest.
The basic idea is to let them cry longer and longer periods of time. Tell the child she needs to go to sleep and that mommy needs to go to sleep. That we all sleep in our own beds and stay there until morning. When they cry the first night you go in and pat them on the back -- tell them they are okay and to go back to sleep. You then let them cry for about 10 min before you go back in. Repeat this time staying gone 15 min. DO NOT pick them up. DO NOT make a big deal about going in the room. Stay calm, pat them a couple of times and say "its night time the sun is asleep and its time for all little girls to sleep too". Plan on it taking a while on night #1. Have a timer you can set so you can make sure to not go in too early. Its not easy --- but I think it is really best for everyone in the family. Sleep deprevation is not healthy.
One last thing -- a bedtime routine is super important --- but I tried to make most of the routine happen outside of their room. We read stories on the couch. When we went into the room at night it was pretty much all business. If they are used to extended singing, cuddling, laying down with them, then when they wake in the middle of the night they may want that same attention in order to go back to sleep. When they are older and have the sleeping thing down, you can move all that back into their room.
That's my experince for what its worth. My girls are 3.5 and 5 now and almost never wake up at night.