I don't feel you were discriminated against.
You brought up dedicating yourself to your family. You opened that door.
We hire LOTS of people who have kids, but it's not an unfair question to ask if they have daycare, etc in place for their children. You'd be surprised how many people say they don't. I mean, it seems to me that's something you'd have in order BEFORE applying for a position. That's just an example. How could we hire someone with children and no daycare plan?
We have employees who are raising their grandkids. Having kids, in and of itself, isn't an issue. And, we work in a very fast paced, high stress industry. There's no point in painting rainbows and roses for someone. That would be misleading. We hired one woman to work in the office and she only lasted 4 days. She voluntarily left due to not being comfortable with the pace of things.
It sounds like they asked you back to get a feel for you and so you could get a feel for them. They chose to go with someone else. These things happen.
They didn't HAVE to offer you a "working" interview in order to cover anything up.
No offense, but it sounds like you went in with the feeling that they wouldn't hire you because you had kids and maybe you set yourself up for failure in that regard.
After my divorce, I hadn't worked in 10 years and I simply explained that we have moved quite a bit for my husband's job but I wouldn't be moving anymore. I never mentioned my divorce, I never said it was because my family came first. I just said that my husband's career required us to relocate often and at that time, I didn't need to work. However, I was ready and eager to get back into the workforce.
It's all in the way you present things sometimes.
I'm sorry you didn't get the job, but you felt uncomfortable for whatever reason. I think it means that the right job for you is just around the corner.
Best wishes.