i have a problem with one of the girls i work with?

ON OF THE GIRLS AT MY WORK PLACE, FEELS SHE CAN GIVE ME ALL THE WORK , THIS ONLY HAPPENS I DAY A WEEK WHEN THERE IS LESS STAFF, I WILL ASK HER FOR HELP AND SHE JUST LAUGHS AND NEVER HELPS ME. WE DO GET ALONG JUST FINE, IN FACT I REALLY LIKE HER, SHE IS A LOT OF FUN TO BE AROUND. WE ARE THE ONLY TWO IN THIS PART OF THE OFFICE THIS DAY. OTHER DAYS WHEN THE OTHER GIRLS ARE THERE, SHE IS JUST FINE. I AM NOT SURE IF I SHOULD TALK TO THE DOCTOR ABOUT THIS OR NOT. I CAN NEVER GET ALL MY WORK DONE ON THESE DAYS BECAUSE OF IT. WHAT WOULD YOU DO.I THINK NEXT WEEK I AM GOING TO CALL OFF ON THAT DAY, LETS SEE WHO HAS TO DO ALL THE WORK THEN.HA HA