Winter may regret not trying to know Marcellus more during her former timeline, but she still can't forget everything he did back then.
Even though he did agree to get married with her, he still went around and flirted with other women. He was indifferent to her existence as he would avoid her most of the time. While she did decide that she would not expect him to act like a loving and affectionate husband, she still thought that he would treat her a little better than that at the very least.
However, Marcellus never did - not until he found Winter barely holding on and losing almost everything.
'Because of that certain occasion, I did not hold a grudge against him. I did not see him as bad as my adoptive elder sister nor my uncle nor my aunt. Ever since he tried to help me, I believe he is good even though it had already been too late...' Winter brooded over and kept silent while Marcellus only continued to pin her on the wall and stare down at her.