What if tenant refuses to leave ?

I have issued 2 month notice to leave for a tenant and they have accepted this and is looking for a place to move to.

She is in the process of a divorce and because her husband has moved out without leaving a forwarding address she has no income and is not paying her rent.

I have several people wanting to take the property and willing to pay a holding deposit etc.

What would happen if the tenant simply does not have the money to secure another property and on the eviction day refuses to leave ?

I am concerned about signing another lease with the new tenant, them giving notice on their existing property and not being able to move them into the house because the tenant decides to stay put at the last minute.