Thank you so much for all the replies. A lot of you took time to type out a detailed response, so I really appreciate it. Unfortunately, there are mixed opinions on the topic which makes my decision more difficult.
To reiterate from my previous posts, when I took them, I was initially going to help escort the mom across a busy road (at the time I had no idea there were babies or I would have observed from a distance). It was dark, 2:45 am. I parked my car inside my neighborhood. As I was walking, the group of ducklings b-lined to me. They saw me before I saw them. In fact, they were actually closer to the mom. Had they not chased after me I probably would have let them be. I put them in my trunk and went to look for the mom, and eventually found her about 150 yards away in a church parking lot. Excited, I attempted to reunite them, but she flew off as soon as I opened my car door (I parked at what I thought was far enough away to not spook her). I waited and listened for quacks, but nothing. She really flew off. Then I heard Coyotes chattering. After having an officer stop by, he suggested I keep them overnight, so I did. I called animal control/rescue in our area the following morning and they said they would just euthanize them. So, I've been raising them ever since. I really didn't want ducks, and I wish they hadn't followed me. But I would have felt bad about running away from them since they were seemingly lost (not following mom).
Anyway, right or wrong decision - I'm in a different situation now and want to give these guys every chance I can at a good life. I tried looking up rehabilitation places, but there doesn't seem to be any nearby (I'm in the Dallas, TX area).
I can find a neighborhood lake, or corporate HQ with ducks. Or, there is a friend who lives about an hour north of me who has a pretty big lake with a bunch of ducks. However, she told me she feeds them bread - and disagrees with me when I told her that it's bad for them.
I don't really have the land to give them a good life that I feel they deserve. But, should I give them the option to choose if they want to leave me? (By taking them out to a good location when they can fly and see if they come back when its time to go)
Edit: Also, another option is a friend of mine who owned domesticated ducks. She gave me some starter advice when I first got them and told me that they were going to keep theirs for life until a hawk got one of them - and that they were considering getting another pair. I could possibly ask her if they want them? But that would mean a life in captivity.
WHY DID THE DUCKS HAVE TO FOLLOW ME!!! (They're cute and all but I hate tough decisions that are full of uncertainty.)