I'm also a lefty who was taught by a right handed knitter. I knit English the right handed way. Again I agree with teaching the way you knit so you can more easily help your duaghter. Usually children find it easier to learn English, and most children adapt pretty well, especially since knitting is a two handed activity.
I also play piano and guitar, both right handed, and when I tried a guitar strung "backwards" I was totally lost.
Another consideration: if she's ever going to work from patterns or charts, they definately have a right-handed bias. A true "left-handed" knitter has the stitches being knit off the right hand needle onto the left needle, therefore types of decreases (left-slanting or right-slanting) have to be switched, and sometimes the directions of cables too. It can get REALLY confusing. I'm a VERY left dominant person, but I can't get my head around knitting lefthanded.
Good Luck and Happy Knitting to you and your DD! :XX: :XX: