Dear K.,
I totally understand! We went through this with our son at that exact same age. I tried everything. I had so many different suggestions, from so many different people, including the...you just have to let him cry...and cry....and cry... etc. I did not have the reasons to not let him cry forever like you do, but despite the advice, I knew that is not what he needed.
It sounds like she could greatly benefit a sleep schedule, for sure... but my son was on one, as I was a stay home mom. And yet, he was still up every 2 hours. Just saying that that may not be the whole answer...
There is s tendency in the world of parenting to think our child is just manipulating us, and we fear that we are allowing him or her to set a terrible pattern. And sometimes that may be the case, but if you struggle with those thoughts, I would resist them.
Our son is now 18 and I know that love never fails, and that there have been a number of times, including 10 months old, where he just needed us to be there for him. He needed our soothing and comfort during a painful and difficult time - whether physical pain (teething) or emotional (insecurity, etc).
If you believe in God and would like some additional spiritual suggestions that worked for us, let me know.
You are doing a good job and seem like a great mom!
MA