In principle, you could ask your therapist under what conditions she would compel a patient to be hospitalized.
The standards for hospitalization may also vary from country to country.
I think typically it's unlikely that you'd be forced to go to the hospital unless you've formed a plan, have gathered methods, or are otherwise at high risk for an attempt.
It's expensive to hospitalize someone, so unless you've got good insurance, a hospital would probably try to discharge you as soon as possible. I've also heard of instances of people outright asking to be hospitalized and being refused.