Husband's ex-wife filed restraining order over facebook pictures?

My husband (who I have one with) also has a daughter from a previous marriage. I have been with my husband since his daughter was 16 months old and try to be a good stepparent without crossing any boundaries (I've never tried to take the place of her mother). My husband's ex has done nothing but try to make our lives miserable from day one, and I always tried to stay out of it. I just received a restraining order however because of a picture of my stepdaughter playing in the bathtub from the waist up when she was about 20 months old. The picture has been up there for years and I never really gave it much thought. My profile is set to private and only friends can see my pictures. She saw the picture and contacted a lawyer and filed a restraining order against me for child endangerment stating I have exposed her to sexual predators. Is there anything I can do? Will this actually fly in the court of law?