Would you be OK with being a 5th or in my friends case a 7th wheel?

Would you be OK with being a 5th or in my friends case a 7th wheel?

I've planned a get away with friends to celebrate some 40th birthdays and everyone is coupled up apart from one friend who is single.
We had a group chat that got started up and we were all joking and then she just left the group.
She didn't give a reason for leaving and she hasn't asked for her money back that she'd paid.
I just don't want things to be awkward.
Updates
+1 y
She knew about all the couples coming along and she was still keen to come along.
There's nothing malicious in our intentions.
It's going to be a boozy weekend and the girl likes to drink so hopefully she'll be joining me for a few cocktails.
Would you be OK with being a 5th or in my friends case a 7th wheel?
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