new mom seems to want to abandon babies

My muscovy just hatched her ducklings yesterday.  This morning, she was pacing back and forth in their area of the duck run virtually trampling the babies.  I closed up the run and opened one side of her area.  She is now roaming the run and the babies are trying to keep up.  I worry that they will chill because it is a little cool for them this morning 70 degrees.  She is not sitting keeping them warm.  She is somewhat protective of the babies but just peeps at me if I pick them up.  I previously had a runner who hatched some  babies and she was vicious.

I went ahead and set up a brooder for them just in case.  I have only had ducklings one other time.  Is this normal for muscovy?  I know that some ducks are bad moms I at least want to give her a chance.

Any ideas/opinions appreciated.  Thanks

Well, she seems to be doing better.  Still not sitting but she is staying near them.  I put a heat lamp in the end of the area that they are in and the babies are now sleeping under it and mom is standing by. 

Okay oregon blues.   I know it is not nearly as cold here. I guess I'm just a worry wart.  I only worry because I know in the brooder they should stay in the 90's at first. 

Ok, I jumped the gun on assuming my hen was going to leave her babies.  Today she is much more protective, not attacking but puffing up and huffing trying to scare me away from her babies. 

Everything is good.  All 11 are doing well.  Eating since day one.  Mom may have wanted to go for a swim that first day, she ended up in the large waterer but has been fine ever since.