I feel so guilty. It's totally me! I'm tired of having to flip to the Beyond manual to do the hands on for Grace. She's not having any trouble with the math at all.
But I think I'm just going to do a page or two a week. Like maybe one lesson worth. We are in unit 8 in LHFHG and she's doing 1A... So I figure if I do it this way she'll catch up before too long. She just turned 6 in January, so I'm not concerned academically. She's just doing so well and she likes it... but I need less right now. I'm also going to slow down handwriting... but that doesn't bother me as much
she's gotten quite sloppy. She's doing ARFH A, so instead of doing a whole page at a time, we'll just do one section (half a page) and do it better. But the math is a decision I've just realized that I have to do. For my sanity. And it's killing me because I don't know that it's best for HER. UGH!
I felt like bawling. 
You know what, he could! And he could do a lot more than "that" too. I remember getting out a piece of paper and writing down everything I was doing throughout the day that perhaps one of the dc could be trained to do, and this was the beginning of our chore charts, which for me have been a lifesaver. I'm just typing this to speak to the underlying tension I am reading in your words here - there is real help on the way, and it's in the form of Jayden and Grace! 
Not every single subject has to be at our dc's optimal learning level. Sometimes, the best choice is the one that gets done. 
I think that your dd is already ahead in those areas for her core guide anyway, so going half-speed with them would be fine. I think consistency is more important than speed in this situation, so I really like your idea of doing handwriting one day, and math the next day. Going every other day like this will keep her consistently doing these subject areas each week and slowly and steadily move her along. I would do this rather than trying to do 1/2 a handwriting page and 1/2 a math assignment each day. Time is taken up by transitions of getting out things and putting them away, so alternating the days instead would work better IMO. Sometimes the best decisions are the ones that are good overall for the entire family. I think that this decision falls into that category and that your dd will not be hindered by it in any way. HTH!