There is no harm in sending a polite text explaining your situation and why you feel your behavior was off. That’s not only cathartic for yourself as a stutter, but also for her given she might’ve felt some anxiety as well. Personally I feel you, unfortunately that is a situation I’ve dealt with a lot the past six years. My unsolicited advise is to express that you’re having a hard time with your stuttering in the moment it initially comes up. Good friends and good people appreciate transparency and honesty, it takes some balls but the confidence that’s comes from openness in the initial moment can be a real blessing. Best of luck friend hope this helped a bit.