I would not force feed a 200g snake. 4 weeks is really not a long time to go without feeding for a bp. Try to feed every 2 weeks instead and let her "miss" food a little bit.

And please don't leave live rats in the enclosure in the future, for both of their sakes. If you want to leave overnight, c/d the rat first so it can't cause harm to your snake. In the morning if it's still there, feed it to your other bp.