Fitting punishment??

*Warning, this post contains a lot of poo, poop, poopy, and crap*
This morning I woke up and needed to do some laundry.  I got it all together, put it in the washer, came upstairs, took Sierra to school and headed back down to switch it over.  As I'm coming back from the laundry room, I notice a bunch of commissary bags laying in the little alcove beneath the stairs.  The minute I saw those bags, I knew it was Autumn, my 7 year old.
We don't ask Autumn to do much around the house, keep her room clean, put her plate in the sink, put away her undies and socks when they come out of the dryer.  One thing we also ask her to do is to take out the dog.  We also have her pick up the poo as well.  Especially since our dog likes to go potty out front where other kiddos like to play.  Nobody likes poopy shoes!  So she is supposed to take the dog out when she gets home from school and pick up the poo if she goes.  So I knew it was her.  We have been asking Autumn recently if she's been going poo, because she was seeming to always come upstairs with the bag...she kept saying no that Lexi wasn't going.  Now how can a dog go 5+ days without going poo??  She was still eating, and still drinking water, so we know that Autumn wasn't a.) paying attention, or b.) not picking it up.  Well the last couple of days Lexi has gone poo a LOT.  Autumn went out twice yesterday with two bags each time, and I guess Lexi pooped 4 different times...wow, I guess it was building up from the last 5 times she didn't go.
Sigh...
At first we didn't think anything of it.  Until I saw all the bags, just thrown down the stairs.  I left them there, called my husband, let him know what was going on, and what I was going to do as punishment.  So this afternoon I picked up the girls, and as we were walking home, I told Autumn that she and I needed to have a talk.  She asked why, and I told her what was going on, and that we didn't appreciate it.  I also told her what her punishment was going to be.  We came home, we looked down the stairs, and all of the bags were GONE!  Vanished!  I don't know what happened to them, I really wanted to leave them there only for the reason that I wanted Autumn to pick up every single one of them.  Her punishment was going to be to go outside and with each of those bags, she had to find other people's dog poo, and pick it up.  Since the bags weren't there, I guesstimated, that there were about 10 bags, we grabbed 10 from the house and we both went outside.  I let the dog walk around while we searched for poo.  Let me tell you, it really isn't easy finding poop in the snow.  Unless the dog has just gone, the snow usually covers it up.  So we walked around for a little while, then we walked another way, finally we found some poop for her to pick (oh and the dog pooped once too).  She picked it all up, and threw it away and came back for more.  When all 10 bags were gone, we were able to come inside.
Now I don't know if thats the greatest punishment in the world.  I do believe the punishment should fit the crime, and I don't think what she did was sooo horrible.  I would like it if she picked up the crap, but there are also adults around here that don't, not that I'm making excuses.  I also hate it when she doesn't pick it up, because I've stepped in the poop before too!  Its not fun, its gross, and then it gets in your house sometimes, ohhh and that smell..YUCK!
I hope she has learned her lesson.  Its only over here that she'll have to do this.  When we get our own place in the states, she'll go out every day after school, not to take the dog out (because we will have a yard), but to pick up the poo for the day.  Its one of those chores that really stinks..ha ha, literally, but will give her some sense of responsibility.  With her issues and not paying attention, she needs some sort of consistency in her life.  Personally, I think most kids should have chores, at least to give them a sense of helping around the house.  Even my 5 year old has chores that she does.
So is this a fitting punishment, or was I too hard on her?  Should I try something different next time?  What do you think?  I'd love to know!