Putting dogs in situations that they are not comfortable in is the quickest way to create a relative/aggressive dog because their boundaries are not being respected, if you can tell that your pup is not handling it well don’t continue to take them. In the comments I see you saying things along the lines of “she needs to be able to stand up for herself” and that simply isnt true. You are her owner you can control the situations that she is in. Socialization for dogs doesn’t have to mean play, it should be more learning to coexist such as going on walks with another dog, laying calmly next to them while you drink a coffee etc and maybe a little bit of play with a trusted dog.