Definitely not too late. Things can only get worse from here unless you seek professional help. This is what professionals are for! You may have to pay more for it, but those mats will hurt until they are removed. Unfortunately this will make her less likely to enjoy the hair cut as well. Be honest with the groomer about what's going on and about her behavior. If they seem unable to handle it, you can always go somewhere else. If you have had issues with the dog becoming aggressive with the groomer, you can see a vet about getting a prescription for some anti-anxiety medication to sedate her a little bit and take the edge off, so that way she is better with the groomer. She'll get a better cut, too, if she's staying still. It can be so rewarding for someone to groom a matted dog and make them look and feel so much better! It's more work, but is worth it. In the future, try to keep her coat up with brushing, and schedule grooming appointments more often. Poodle hair is a lot of work.