I would be upset at the cancelled session(s), yet understand that crap happens & that other people (Ts included) can have 'emergencies'.

I am not going to hold it against T. I would extend them the understanding I would hope to receive if the shoe were on the other foot. It does not mean not bringing up any upset that may have been experienced at the missed session but, again, I would not be resentful or angry at them about it.

Depending on how long they are unavailable, you could ask them if there is anyone else to cover for them. It might not be easily or quickly put into place depending on what T has on their plate (e.g. not able to check or return client massages), their client load, the willingness and/or availability of a suitable 'replacement' and so on.