Lexi loves to fetch too, but we only play during our once a day "training sessions". Otherwise the big dogs get involved, and they destroy even the toughest of toys in 5 minutes.
Do you ever hide the toys for Daisy? That might give you a breather!
, I'll distract lexi then throw the toy in the opposite direction, then I'll hold up my hands and go, "where is it?!" she's off like a bat out of hell and won't stop until she finds it.