Well after crying for an hour and a half, she is now left to wonder if anyone will EVER come to get her any time she is put down! Babies cry for a reason. Mainly that is the only way they can communicate. She could be saying: I'm scared, I'm hungry or thirsty, my teeth hurt, my tummy hurts, my diaper is wet, I don't want to be alone, could somebody just come and hold me and let me know everything is OK? Or even I've crapped all over myself and the crib and it's pretty gross! Friends of ours ignored their daughter's cries for over an hour that started at 6am just because they did not want to get up yet. When they finally went to her after 7am, still crying, they found poop everywhere! So you just never know the reason! A baby is seriously trying to communicate with you!
Personally I don't think anyone should ignore any baby's cries. For me, 10 minutes is too long for a baby to be left alone to cry. A parent's job (or care giver) is to meet their needs. Figure out why they are crying and fix it. Babies under a year need lots of love and touch. They need to feel that someone cares about them. I've had my baby cry while I held him for longer than 10 minutes, but that is different. He knew I was trying to help! The cry changes when you're holding them.
I agree with the other person who said it leaves psychological scars for a baby to sit alone and cry that long. They lose faith that people care about them. They grow up anxious and jumpy, they don't trust many people in life yet don't know why. Wouldn't it be so much better if your child grew up happy and secure and was able to be left with sitters without fearing how she would be treated?
On that note, I would have a serious discussion with your family who has been watching her. They are grossly slacking in their duties to that little girl. If you can, look for other child care providers. Many are happy to hold a baby and figure out why she is crying. They actually enjoy it. It might be worth the price to avoid the damage that is being done to her. I know people who charge under $30 a day for quality child care.
Also if she has had surgery or something, expect everything to be upsidedown for a month or more! She might have setbacks or developmental delays, perhaps she was about to crawl or walk before the incident and now has reverted to laying, rolling, or sitting in one place (or only crawls if she was about to walk before). She needs extra hugs and human touch to know her world is safe and people love her. If you are single, try letting her sleep with you in your bed for a while. Don't put a time limit on it, just see how it goes. She needs comfort from her mama and that may be all you can give since you do work. I promise she won't be in your bed forever!