Wow. VERY similar to my family. I, also, had bladder problems as a child and a couple surgeries later, I eventually grew out of it. My kids have all used pull-ups at night until at least the age of 9. My boys were very embarassed, so I knew it wasn't a laziness issue with them. As others suggested, limiting fluids, waking them to go before you go to bed, etc. Yep, tried it all. I even took the oldest to the pediatric urologist to make sure it wasn't a physical issue.
First of all, let me tell you that I recently learned that kids who are "gifted", have more of a likelihood to have these problems. My kids (despite my husband and my very average brains...LOL )are very bright- in the TAG program, blah, blah.. It was explained to me that their brains are so intense and engaged during the day, that they just cannot wake themselves to pee at night. This totally makes sense, because my kids sleep through EVERYTHING! Fire alarms, house alarms, thunder storms, dogs barking, you name it- they sleep through it. SO, no wonder they don't wake to the "urination signals" the brain sends out. Several doctors have told us that they will outgrow it, it may just take them longer than most kids. IT's not their fault, they really can't help it.
Ok, that being said, we DID buy the Wetstop alarm for my oldest about 4+years ago. He used it for a couple weeks and was dry. He hated it, but used it. I then tried it for my second son, but the dang thing didn't work right. So, I bought another one and before I had a chance to use it - my son started becoming dry. So, I tried it with my daughter at one point and the dang thing (second one) quit working. ARGH!!
Just recently, we decided to try again with my daughter. I purchased, yet another, alarm. THey have redesigned the Wetstop and this one works better. My daughter really, really doesn't like to use it, but she has also admitted to just going in the pull-ups because she doesn't want to get up. She does also sleep hard and cannot wake to go. I told her it was time......
I think one of the biggest challenges is finding the right time to start. We will have to have my daughter sleep in our room, because the alarm is not loud enough for me to hear it in her room, even if the doors are open. We used the alarm one night and it took awhile for me to hear it (and she was in our room on our floor). It seems there's always something "coming up" - a sleepover schedulee for her birthday weekend, guests staying with us, me being out of town, etc. So, finding time when I am able to have her sleep in our room and be able to get up with her is the hard part right now.
If you have a monitor, you could put that in your kids' room - turn it up loud, because, like a said, the alarm isn't too loud. We couldn't do this, because we have a monitor already for my toddler, and the two cancel each other out.
I think the alarms work well . I have only tried the wetstop brand and was assured after the second purchase, that they had been updated and the bugs were worked out. I have researched the effectiveness and it seems most kids become dry after using it. It's what our pediatric urologist suggested.
I think the investment into the alarm is a good idea. You have potentially three kids that will use it, so you'll get your money out of it. I would say to make sure that if there is a while between uses, clean the sensor and make sure it is dry. Possibly one of our issues was that it corroded and that's why the sensor didn't work after awhile. Not sure, though-just a guess.
Good luck to all of you! :)