I also feel that 'yes' on Collins is all but certain, then again, it's women's tennis we're discussing so anything can happen.
Heck, I thought 4th round was 1/8 finals since she started playing in 1/64 finals so thats basically her 1st round. The question was even rephrased that way, "while losing maximum 1 set in the process" There is no way for her to lose more than 1 set and progress because if its 1/16 finals then she is only going to play only one game thus technically she cant lose more than 1 set to progress
Exactly my reason for going with "No", all she needs is to drop just a set

She needs to lose the game