I offered to pay my girlfriend's (28F) bills so that she only has to pay me one bill and she thinks that it's condescending?

I (25M) had a conversation with my girlfriend about money and I told her that I make a lot more than she does (literally double) and I offered to pay her bills for her so that she doesn't have to pay multiple bills (cell phone, car insurance, car payment, etc) and instead she would just pay me one bill and I would take care of everything for her. She looked at me like I was crazy and said that's not a serious offer. I told her it was a 100% serious offer and she told me that she's an adult and she can take care of herself and that I shouldn't make her feel like she couldn't take care of herself. I told her that's not what I meant and I just wanted to make life easier for her and she told me that she can take care of herself and doesn't need to be babied. I told her that's not what I mean but she won't listen and she keeps saying that I'm being condescending towards her. I just don't want her to have to pay all those things and want to help her because it's not like I'm hurting for money. I don't know how else to explain it to her without sounding like I mean to talk to her like a child. Any thoughts on how to approach this better?<br><br>Edit: maybe I called it the wrong thing when I said one bill, maybe it was a bad choice of words because reading the comments I see a lot of people think I meant pimplike arrangement when it's nothing like that. There's no strings attached when I offered to pay her bills. I just want to help her because I don't want her to struggle. I've seen her work 3 jobs at a time just make ends meet so I'd like to help her out and make it so that she doesn't have to struggle so much. She can go out and buy dinner and not feel bad spending money on eating out once in awhile. She can go shopping and not feel so bad about spending money or had to keep track of how much she's spent. And it's not that I'm trying to keep track of what she spends her money on. I just want her to feel a little bit more comfortable when she's out and she doesn't have to worry about money as much. I just want to help her have a better life and I don't know of any other way to do it.