Getting a urine specimen from mom is difficult. How do I do this?

She has to urinate toilet then i get the specimen. She can't hold the cup underneath. i do this and we end up with it all over the floor. can i get it in evening and put it in refrigerator until late am when we go to lab. help. how do i do this.she can't do it in lab so we do it at home with sterile container.