Hey Peggy, my DS is 19 weeks and also has a dummy at bedtime, for naps during the day, and for when we're out and about if he starts getting grumpy!
I am not sure when/how we are going to wean him off it, but I wanted to respond to the bit of your post about putting the dummy in throughout the night: it really reminded me of a situation me and DH were in about 5 weeks ago, when DS was the same age as your daughter!
Literally, we were getting up LOADS in the night to put his dummy in. The worst night, we had to do it SEVEN times between midnight and 6.30am! After that night, DH and I decided it had to stop!!!
So....we decided that DS needed to learn to settle himself back to sleep without his dummy. We decided to concentrate on the early part of the evening at first (ie between 7pm - 10pm) as this is typically his deepest, most settled kind of sleeping. So when he stirred at 8pm, having been in bed for an hour, instead of rushing in there to replace the dummy, we waited in the living room listening on the monitor to see what happened if we didnt go in. Obviously DS is too young for 'controlled crying' and I would never leave him if he was in distress, so we listened carefully to the cry he was making: it was a sort of moan like a creaking door! Definitely a 'tired' noise rather than a cry of distress. We left him alone and within minutes, he was back asleep!
For a few nights we carried on going into him in the wee small hours to replace the dummy, mostly cos I didn't believe he would also be able to self settle late at night on his own! But we kept it up in the early evening until we were confident (after maybe 5 days) that he had got it nailed.
Then we decided to try the same thing in the middle of the night: now, when he stirs and cries in the night, I look at my phone to check the time, and say I am going to give him 4 minutes to go back to sleep (it can feel like a looong time at 2am!). About a week later he had got the hang of this too. He usually grizzles/moans for 3-4 mins and then drifts back off to sleep....it doesn;t work all the time, but I would say it isi successful 70% of the time. Which means we now usually only get up once to replace the dummy, and he will wake up another 2 times but will go back to sleep on his own. A much better night's sleep for all of us!
The one thing I have noticed is that if DS wakes/stirs anytime from 5am onwards, we still have to jump out of bed to pop the dummy in if we want any chance of him getting back to sleep! It seems like the self settling works v v well before midnight, ok-ish between midnight and 5am, but after 5am: no chance!
Might be worth a try? Good luck!