Should I still cover a shift after my scheduler replied so late?

So last week Thursday July 23rd the work scheduler asked me what's my availability for a specific client? I have a second job so I asked well what is open especially since there are several other people on the care case. She said I'll get back to you tomorrow Friday or Monday July 27th once I get everything updated to see what is open August. After she said that I sent a text that night Thursday (July 23) saying I can work Saturday 7am-7pm. I heard back from her today July 29 saying okay I plugged you in. Like no offense but it took so long that I started coming up with other plans. And even when she sent that she never gave me what is the openings. Would you say I waited to hear back from you but didn't no I'm no longer available Saturday or just cover the shift?
Should I still cover a shift after my scheduler replied so late?
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