Was Alice supporitve of George's business?

It probably just wasn't her cup of tea. I imagine she and George worked together before the kids were born. After that, Alice decided to be a stay-at-home Mom and let George be the breadwinner. When he asked for her to come back to work, Alice decided to give it a chance, for George. Then it didn't work and she realized she didn't miss the working world.

She wanted to be a Mom first and a businesswoman second, it was just her personal decision and it was what she valued. I don't think she liked leaving the kids with the babysitter because she wanted to be the mother, not some stranger. She didn't know that those two people were corrupt but she just didn't trust them. The reason she was able to pick up on that and George wasn't was because George was so blinded by his ambition and Alice was able to see the situation with an objective view. As for Emily falling in the pool that isn't George's fault, Alice is just saying that she feels it is a sign that she needs to be with the kids.

I just assumed she was having an affair and her boyfriend would be visiting during the day. Seems logical to me.

Between a neglectful sitter and a corrupt business couple, it was clear Alice was a stay-at-home mom all along.