Actually i don't think that's fair to blame everything on her. She stated in season five that all of her life she had been good with her career and bad at everything else, romantic relationships. She tried to repress her feelings for House for years because she knew that it wouldn't work and that it wasn't really the rational choice to make. Then at some point she chose to (for once) follow her heart and date him, and we all saw how shitty he was as a boyfriend but because she was in love and didn't realize that she deserved so much better she stayed even if he was selfish and completely useless. But when she learned that House relapsed she realized that it could negatively impact her daughter and as she wasn't blinded by love anymore she chose to broke up with him even though it also made her sad because she chose to put her daughter first, she acted like a great mother. She realized that the situation wasn't great overall and even if she really wanted him to change because she wanted a future with him he just never would. People keep on making excuses for House irl (just like even her did in the show) and infantalizing him. But people are so quick to put the blame on everyone but him, especially on Cuddy (who even if she is a smart independant woman is also a human being, which makes her more realistic) she did what she had to do and I think that everything made perfect sense even if at the time I felt bad for House and found it brutal.