You guys have had a lot better luck than me. I pulled DD out last September, exacly the way you did. I too thought that she won't miss much as school had just started. Well, what do you know, the teacher told me at parents/teacher meeting that she thinks she that weak 'put her back'. BTW, DD is in grade 1. So now, my MIL is sick in Australia and we want to take a trip before it is too late. We have no choice but to go now as it is winter there during our summer break. I have booked this trip around March break, so DD is losing only 2 weeks. I say 'only' lightly, but I still had to sign the form that said that she will have to make up on her return in order to be 'promoted'. Again, this is all for Grade 1. We will have to do Disney in Summer from now on.
Enjoy your trip.
I'm glad you are going to Australia to see MIL and taking your daughter too.
Don't think that just because this year it has been tough means other years it will be. I know when DS was in Grade 1 he really struggled (three different teachers and no consistency) and now is at the top of his class in Grade 8. It clicked in Grade 7 for him. Back in those days Grade 1 was very important because that is when they really work on reading but I think the curriculum keeps changing and they are reading in SK and JK now. Each teacher is different when you approach them. All our teachers really support us taking the kids on trips and only one gave a lot of homework to DD. We got back from our trip - Family wedding in California combined with a bit of sightseeing for 10 days - and DD was about a week ahead of the class, so she just sat there. And we had lugged textbooks to California. Never again. This was for a child in Grade 4!!

DD is in Grade 9 now and we are going to Florida over March Break and then tagging on a few more days.
I do think it is much easier to take kids out of school in Canada from what I have seen on these boards. In the US they can fail a child for truancy for missing too many days.
P. S. if your daughter is struggling with reading - the book I used for DS was Reading Rescue 123, recommended by the school and really worked for me to work with him at home.