I know this would be difficult, but you could try asking her this question. I've asked my T if he was sick of me before and if he wanted to keep working with me.
But there could be many reasons she's had to cancel, like her own illness or chronic health condition, a family member's illness (especially if she has young kids), an emergency with another client, car trouble (well, unless you meet virtually, and then a power or WiFi outage could be a reason), etc. If it is about you (which it most likely isn't), then she should talk to you about whatever the issue is, not just cancel.