Can I legally stop my ex's girlfriend from posting pictures of my 10 month old baby on the her (girlfriend) facebook page?

My baby's father recently moved in with his new girlfriend. I feel she has overstepped her boundries by posting a picture of my baby on her facebook cover picture. This women has only been in the company of my daughter and her father on 4 occasions and doesn't really have any relationship with her. I am deeply offended and want to stop her from doing this.