Heaven, if there's one particular day sleep that's better than the others try putting her down for that one. I wouldn't bother with the others though, cause it's just more stress (and less sleep).
Concentrating on night sleep is easier. Once she gets the hang of it, you may well find that the day sleeps improve all on their own. The most important thing for now is that she gets enough day sleep so she's not overtired.

When we did the NCSS, we found that day sleeps started working once DS was able to put himself to sleep in the cot, not before.

good luck (as always)