She probably watches her phone for news on her child(ren) (where they are needing to be picked up from, what time, etc.) since she did share with you that she picks up her daughter after your session. It feels cold to me; my T has her phone face-down and on silent during our sessions. However, not sure my T has young children or has made arrangements to not be contacted during work hours.

I don't think she's bored with you at all! And she was probably upset that you had reached a turning point and had to be interrupted, as well. Please talk with her about how it makes you feel, uneasy to open up again, and that you want to bottle it all up again. That would be a setback, hopefully you and T can work through this one. Good luck!!!