I just finished a light third draft of my Upper MG short story collection. Since I don't know what problems are left I think I should start looking for betas, but I'm afraid my manuscript is too long. Most Upper MG novels are 20,00 - 55,000. Mine is 61,000, but it is also a short story collection, not a novel. Does the fact that mine is a short story collection mean that it can be longer?

Thanks in advance for your help.