It’s funny you say that about your two girls, mine have now just discovered this machine (they don’t even flinch at anything new that comes in) and the one especially is on it all the time. It’s an eye opener for me. She is dancing away while she plays to all the songs... PRICELESS.
It has to be made to drain. The best advice is to slow down this game which more or less urges you to keep a fast pace. Almost all shots can be reached from both sides - no other game allows you to hit both ramps and both orbits (right is hard) from a stopped position on either flipper. This means the control for drains is with you, and the game does a great job of making you instantly pay for missed shots. You have the option of hitting controlled ramps and orbits, and lighting the dangerous target modes when the jukebox is lit, and a MB is ready.
For a game that's rules define risk and reward, the punishment is a must. If it wasn't like this, you lose a lot of the risk factor. I know it's frustrating, I have been there and have got all philosophical about this to justify the tough play.
Other machines have different types of objectives in mode play, but this machine's rules are solely built on a very tight and dangerous risk and reward play. If the ball is in play too long all the time, the song jackpots and other jackpots will grow too big all the time, and then you lose what rules are trying to accomplish.
Just accept that it is a very fast, and hellish drainer (no pun intended), and that IS the beauty of this machine. I have people that are drawn to it all the time, and this is what I have to explain to them when they inevitably complain about how fast their balls drain.
As much as it frustrates you, and anyone else, I bet they keep coming back harder and harder don’t they? There is a reason for that! 
Oh yeah, and nudge!
Cary, NC
Brisbane
