Hi.
she has been very demanding lately, does not want to share toys, or I should say rips out EVERY toy from other children's hands and then tries to run away with it. My efforts have been unsuccessful so far, she does not listen to rationale, reasoning, consequences, or books about sharing. I even tried time-outs which I am not a fan of.*
At 2 yo. The children are usually in an "egocentric" stage, it would not help any reasoning talk you have with her (her brain still developing and those skills are slowly acquired)

You have two options:
1. Let this family go (which personally I think would be easier) or
2. Stay strong and help her to develop those skills through role modeling, songs (with sharing themes), pass a toy in a group making sure each has a turn more than twice, that will help her to realize the concept that the toy (object) is there and will come back. Also, do not lecture short simple sentences is what they understand most at that age. "Egocentric" mwas that they do not have the ability to thing or feel for others or other perspectives taken, her brain is kind of working in this mode ie. I see it and it's mine, mine.

Challenging yourself by guiding this child will help you in the long run, because this is a normal behaviour for two years olds

Secondly, she has only napped with me a couple of times but I ended up rubbing her back for about 30 minutes. This was about a month ago. She will be increasing to full days now, which means nap time. She is already in tears and calling for her mama just after lunch and I have tried a couple of times to put her down, but no luck. I have tried singing, music, white noise, rubbing her back for 5 minutes
I notice that she is full of energy (to do what she does at nap time), I usually with no exceptions old and new make them fall asleep in no time. They need active physical work, tire her out. A walk sitting on the stroller or sitting on a swing won't help. Now that the weather is nice take her to the park take a ball make her run, play catch. Use bubbles so she can run. Exercise and plenty of water. They usually comeback exhausted and hungry. (Usually with no energy left) they fall asleep in no time after their lunch time :0)
Each child has different levels of energy I mostly cater to that. Some need more exercise and some not as much but in general they love to be outdoors. I do sit beside the new ones and wait until they fall asleep (takes less than 5 minutes in most of the cases:0) after the third time they are in routine and I do not need to sit beside them anymore.

I hope it helps.