For over 25 years I have known and seen "Two Girls" (friends) hitting tennis balls together, usually once a week and for approximately 1 1/2 hours a session. As a young pro, I would look at them and wonder, are they ever going to play? Why do they just hit the ball back and forth? Are they trying to get better?
Now as an older coach, I look at them and say to myself, they are still friends for all these years, they have kept themselves in excellent shape, it forces them to get out of their houses and enjoy the outdoors. They sit and talk and have a drink when they are finished and they are having a great time. I have seen them hit one ball over a hundred times. So, who is getting the better workout and who has the most control? Hitting the ball back and forth might look mundane to some people, but if you try it, you will be amazed how difficult it is and how much control you must have.
So, these "two girls," now "two women" have found a way to maintain their friendship, their fitness and just as important, the "love of the game." So, congratulations, you two. I would say you are role models. If you just counted the number of balls they have hit, it would be as much as a person playing 2-3 times a week. They just have not gotten caught up in wasting all weekend to play 2 matches in a tournament. They have not gotten caught up in wondering if they were going to play for a team or whom they would get partnered with or what their ranking is. I think they get the "last laugh," all the fun without the drama.
Good luck on the courts!