Iucounu, I know she'll be fine whatever, but she gets such a kick out of new cool tricks!
There's no harm in skipping around in a curriculum, as long as you teach depended-upon concepts before dependent concepts. That is, you can create your own order as you go.
I also just discard things entirely from the curriculum. For example, I haven't taught my son much about measurements. The NH state standards require teaching about liquid measures, etc. beginning earlier than third grade, IIRC. Though my son has done a lot of work with fractions already, I just didn't think it was important to teach him the relationship between quarts and cups. It wasn't a foundational skill for anything else, and didn't increase his math knowledge, but was rather a real-life skill that tends to be lumped in with math because it uses math, and might provide some concrete examples for practice.
I just think that you shouldn't let the fun looking-ahead stuff take up too much time, since it will be to the detriment of other stuff that might need more time to absorb and is holding up whole areas of development.
BTW I probably misused the term "relative weakness". I think that some things are inherently much easier to understand and learn quickly, especially for an abstract thinker, and that the ease of picking these things up might bear no relationship to their place in the curriculum. It might be that coordinate graphing appears so late in some curricula just because the authors didn't find a way to stick it in earlier, and/or didn't think it would be hard to pick up quickly, and/or didn't see the need to introduce it until just before dependent concepts.
So failure to come up to speed as quickly in other areas might be quite natural, and even in line with the intent of the curriculum; they include that stuff earlier and spend more time on it because it takes time.
I really think you should check out those workbooks. They're really fun, and you can find plenty in them to stimulate your daughter. And I guess I wouldn't shy away from teaching her whatever she wants to learn either (for the record, I let my son zip ahead on a range of different graphing too). You just have to realize that you're maybe creating a bit of a mess for yourself in keeping track of what's been done and what hasn't, but it shouldn't be insurmountable at this stage.
FWIW I think that's the greatest benefit of an online learning website: it can record your progress in different areas. That's how I use IXL: I can look around and see what we've done, and what hasn't been done, which lets us skip around to our heart's content.
As to rote learning, I am actually spending a few days focusing on that.
We initially sped through the times tables in a couple of nights, which left my son with a lot of math facts which he started knitting together, but without the instant facility that would speed up doing other math work. Now we're going back and painstakingly doing each number using a couple of "Math Mammoth" techniques (thanks La Texican), noting interesting number relationships, etc. and not going on until he's rock solid.
So we did one night on 8, then one night on 7 and 8 (with the latter just sped through super-quickly for reinforcement), then one night on 6, 7 and 8 (with the latter two sped through). Tonight we do 5, 6, 7, 8, and 9; then tomorrow, 4-9; then Sunday, 0-12. He has never had trouble remembering any of the facts for 3 and below.
I usually don't encourage my son to rote-learn anything, but for multiplication I just think it will increase his processing speed a good deal on a range of problems. So far the plan is working: we spent about 25 minutes last night doing 6-8, and tonight anticipate spending about 30 minutes on 5-9. He is enjoying it because he knows he's working towards a goal of being flawless on multiplication, to the point that he will never have to memorize it again. Then we're back to the mega-fun stuff.
