No problem, I never know how much to share. I can be pretty long winded. not sure where to start.
The montessori school put DD8 in K at 4. We were surprised since we were clueless about what was normal for her to be doing at that age and although we were concerned about maturity issues we let her go to K at 4 (TGiving Bday). She did fine. DH was set at this point that DD8 needed to be with her age group eventually. She is little for her age and he felt very strongly about her being with her age group and being the oldest vs the youngest. At the end of her K year I went to visit the PS K. I came back and told DH that no way could I do that to DD8 since the PS K was going to spend months learning letters/numbers/colors/shapes and she was reading well and was telling time, money and adding/subtracting several columns, not to mention other math skills.
So we left her at montessori for 1st. The Mont. was always showing us her work and what needed improving, but there was no mention of level of work. We were also fairly clueless about what the SAT-10 results meant since the GEs we felt were probably inaccurate based on the definition we read. I had wanted to leave her at montessori another year but DH was concerned she would be left out of friendships if she didn't move now and most of the private schools that go beyond elementary are very inconvenient for us.
I was sort of 50/50 on putting her into PS 1st or 2nd grade. DH wanted her with her age group. When we met with a 1st and 2nd grade teacher they looked at her work and said she would do fine in either grade but made no recommendation threw around buzz words like differentiation. We fell for it. So we put her in PS 1st grade and other than some harder spelling words last year she hasn't been challenged last year or this. We had no idea how far ahead she was.
Anyways, I wish I would have left her in Mont. because she has stagnated to some extent and is now a bit reluctant of challenges. I have started supplementing. I am going to feel much stronger about having DD4 stay until at least 2nd grade and also doing private testing so we can bypass the group testing.
I should say DD8 is happy though so that is what is important. I recently asked DD8 if she wanted to take the tests to skip 3rd grade and she said no she's fine with extra work from me and staying with her friends and next year she will be clustered with a GT certified teacher. (can't blame her I did something similar in school to my mom). Of course she may change her mind later, she's more fickle than I am.
I don't know if any of this helps you or not. I know $$ are a concern. I know this will probably play a part when DH and I discuss what to do with DD4 but I figure I can get at least thru 1st since we did that with DD8.
And he knows how I feel about the PS decision for DD8.
DD8 lets us know sometimes as well when she has her "why was I held back moments" when she sees some of the friends that used to be with her. At the time we felt we were doing the right thing overall. (ie not being 2 yrs younger than some in High School). So Elem. may be tough but we have wonderful jr high magnet and many HS options, dual credit, etc.
This ended up way too long, so sorry.