Hello, No, this is perfectly normal. Many even sleep with their favorite balls. I would suggest having a time to play on and off thru out the day, BUT show the JRT that sometimes we have to put the balls up to REST. You can have them help you put the balls in a basket and put them on a shelf. Let them see where they are, but tell them it's time to REST!
Mine is a balloon obsessed JRT-- once a day we play and then if she doesn't pop it, we put it up high on the top of a shelf. She knows we'll play again tomorrow. And no, she never lets me forget it's up there the next morning.