, нужно исправить ошибки: If Joan didn't have problems with her stomach, she won't be in hospital now.
If Jill isn't ill, she wouldn't stay in bed.
If you told her the truth, she will forgive you.

If Joan didn't have problems with her stomach, she WOULDN'T be in hospital now. (she has problems + she is in hospital)

If Jill isn't ill, she WON'T stay in bed (she won't be ill + she won't stay in bed).

If Jill WASN'T /// WEREN'T ill, she wouldn't stay in bed (but she is ill + she is in bed).

If you told her the truth, she WOULD forgive you.

If you TELL her the truth, she will forgive you.

возможно исправить для первого либо второго типа условных предложений.