We don't know the final result, but she believes that good deeds will be rewarded. She has done so many bad things, and she will be repaid sooner or later.
She doesn't think her leaving is an escape, she just leaves more opportunities for them, a love that she can't get, and she hopes he can be happy.
Well, no good thing can be taken by one person. The road you choose is yours, so you have to grit your teeth and swallow it.