Got a little surprise pregnancy and I'm not sure what to do

I have three breeding females, all of them get along very well together. The father of this litter wasn't a planned breeding. We had a male off the grid for a week or two, and he got all three females pregnant. None of the females were supposed to be bred, but the little guy was very handsome and I figured I have made worse decisions, so I decided to leave him intact. When I say the mommies get along really well, I mean they get along *really* well. They all sleep together in the same bed, and they all go to the bathroom together. They have never had any squabbles about anything.<br><br>The first litter was born two months ago. This female was already pregnant at the time, but she didn't know it yet. So, all of the mothers spent the first two weeks with the litter, helping the first mother out with all the babies. Eventually, they started to get a little too eager to adopt some of the babies, and I decided to split them up. (This was the night before the puppies started biting my ears to nurse, because they don't sleep well but they know that biting my ears will make me give them food. So I removed the extra moms and all three of them were waiting outside my door and all of them were looking at me like this is all my fault.)<br><br>Since then, I have been rotating all three mothers in and out with the babies every night. So I've been waking up to usually two extra sets of moms and three babies - two of them are still waking up to nurse, and it's very cute. I've been rotating them in and out for a while now, and it started to seem like something was off. The first mother had given birth two months ago, and she was still acting very maternal. This is a pomeranian, and they are known for being good mothers, but you would think she would have forgotten about all this by now. And then there was the other mother, who still hadn't given birth yet. The father was intact, and I took them outside together every day, so I assumed she was just having a really long gestation period. I felt her belly and she felt pregnant, but I just thought she was taking a little longer than usual. Then, three days ago, she gave birth to four healthy puppies. And the first mother, the one who already had two month old babies, she was acting like she just had babies too. I came home from work and I smelled a very bad smell in the bedroom. I opened the door and I saw the first mother, and she had blood all over her fur, and she was licking her vulva. I looked around and I was like, "Where are the babies?" And then I looked at her and I saw two little spots of blood on each of her nipples. I pulled up her fur and I saw two little puppies. They were dried out and clean, and the mother was acting very relaxed, so I think she gave birth a few days ago. The father had been on the grid the whole time, and I hadn't seen him with this mother at all, so I assume she was already pregnant when I took him off the grid. This is not a big deal for poms, though, because we can breed them at six months old.<br><br>So now I have two litters and three mothers. All of the mothers are in the same room with all of the babies, and we're going to stay that way for a few months. The first mother is still producing milk, so she's been nursing both litters. The second mother is also producing milk, and she's been nursing all three litters. The third mother is the most experienced mom, she's done this several times, and she's been nursing all six babies. She's also been adopting some of the babies, and I can tell she's a little surprised there are so many of them. I haven't had any issues with the litters so far, and they all look very healthy. I'm a little concerned it's too much work for the mothers, but they all seem very happy and relaxed. I'm also a little worried the dad is going to get a little too clingy with all the babies running around, but he's been a big help so far.<br><br>So I'm just wondering, is this something people do? I'm not an experienced breeder, and I've never heard of this happening. I know it's not very common, but it seems to work pretty well, so I'm curious if this is a common thing.<br><br>Tl;DR! Three mothers, two litters, one happy family.