A drama about a confession twelve hours before an execution, a once kind-hearted and loving single mother is placed on death row for murder when her son is hospitalized after being constantly bullied because of his sexual orientation.

Try and stick to 25 words. It's good discipline and helps when you're trying to keep white space in the script too. Here are some ideas:

A loving (heart-broken? Or better still think of a new, uncommon adjective) single mother is placed on death row (and battles with who? The justice system? or what? her heart?) after her son is hospitalized (can you be stronger - savagely beaten? Or something stronger) because of his sexual orientation.

Maybe...

When a boy is left half-dead after a homophobic attack, his broken-hearted mother takes revenge, but finds protecting him harder from Death Row...

Just ideas...take or toss out, as you will :)

1. The lead-in feels jumbled and confusing. 2. Whose confession is this? 3. It sounds as if the single mother is placed on death row because of the confession. If so, who was originally scheduled for execution? 3. Hospitalized? Is this an overnight stay? Is her son a vegetable? How far does the bullying go? Is there physical violence? "Hospitalized after being constantly bullied" seems a matter for the school principal or the cops (or both) but not (as it stands) murder.

The log line should be tighter. It also reveals the ending.

Maybe: When relentless bullying goes too far and her son ends up in a coma, a normally kind-hearted and loving mother decides it's payback time.