Many of my adult ball pythons will only eat every 10 days, some of those that are in their teens will only eat every 14 days.

Just an observation: Are you feeding only weanlings to her? Maybe she's just tired of snacks and needs something more her size?

I agree with derrabe: Don't worry just yet. If all other issues that could cause her to go off feed are not a problem (temperatures, stress, etc.), just give her a seven day break, then try again.

Best of luck and keep us updated.