Can I revoke a lease offer? Got a better applicant

This morning, I offered a lease to a family. They haven’t yet signed the lease or paid the deposit. They wanted to start the lease later than I offered (6 weeks from now).

Then I got an application from a highly qualified applicant who wants to move in in 3 weeks! They want to stay longer as well. Better income.

Can I revoke the offer for the first family?

The reason they didn’t sign was because they wanted the lease to start 1-2 weeks later. I counter offered to start 5 days later. But then I got a better application.

This is what my email told the first family:

“If we have not received the items above by December 11 at 7pm, we reserve the right to offer this home to another applicant.”

What can I do? Thanks!