surprising gf with flowers and present at work?

Things have been rough with my gf lately because of talking to my ex and not being physically close with gf around my ex when we would see her about 3 months ago. We have been together 7 months. I had some weirdness but I am totally over it now. Things were getting a lot better when out of the blue one of her co-workers told her I called my ex and told her I love her still. It absolutely did not happen but it looks really bad to my gf. Co-worker is friends with my ex and they are trying to break us up I suspect. I have tried to talk to my gf about this but she is confused and doesn't know what to believe and she doesn't know how to trust me now because she thinks I am gonna hurt her. I tell her how much I love her and that I have no feelings for my ex...don't want to get back with her or anything. We are still "together" but it doesn't feel like it to me. I confronted the co-worker whom I was friends with and she lied about at first and then admitted to saying it. I told her off and dont speak to her anymore and I told my gf what the deal was and how it went down but she is still distancing herself from me. She says she loves me and misses me though. I enjoy sewing and I made her a really nice hooded fleece sweatshirt(from a pattern so it is nice), I want to surprise her with that and roses at her work when she gets there because I won't see her for Christmas. Is that going overboard...I don't want to push her away if she needs some time and space. What do you think?