Hello, fellow Canadian! Welcome to the boards!
This is our first year with HOD so I can't give you specific placement help on the guides but I do second the idea to call HOD and let them help you. I emailed them with times in the following week that I would be home and they called me back. Both times their help was just the nudge I needed to know I was on the right track. Before you call, though, go to the following web page (which it sounds like you have already considered) and print it off and highlight the best placement for each subject (though, from experience, sometimes it's hard to tell until you get into using HOD exactly where your child might place - we've had 2 switch guides 3 months into our year.)
http://www.heartofdakota.com/placing-your-child.php That knowledge before you talk to them will help them give you the best advice.
I'm not sure what you're doing/using this year but you might want to consider starting grammar this year. Last year while still using a different curriculum I did the first half of R&S's English 4 with my then-6th grader, allowing him to be doing the second half this year and not feel "behind" (even though he'll still be behind the HOD recommendation to finish R&S6 by Grade 8, I'm okay with that since R&S is advanced). If she's had no formal grammar or doesn't do well with it, I'd suggest starting with English 3 this year and see how she does with it.
HTH & welcome!
Blessings,