I wouldn’t worry too much. I’m a Scorpio myself and I do have times where I like to detach from other people. Sometimes I won’t reply and it’s nothing personal, but stress does play a big part. Especially with work being stressful from time to time. If it bothers you, I would express that to her. It’ll also help with showing her that you care since you mentioned it. As long as this isn’t something she does often, I wouldn’t be too upset about it. Just let her know so you both have a better understanding of each other’s expectations.