So you have raised children, ran a home, managed accounts and done 100 other roles but they choose someone who has never held down a full time job. Brainless.
The idea that a SAHM can write "CEO of the family" on her CV and that be taken seriously is - if it was ever true that companies took it seriously - so far out of date it's lost in the mists of time.
Frankly? Companies have a lot of choice. A LOT. They literally don't care about your life outside work, no matter how much nonsense they spout about being a happy family and a team and work-life-balance. We all know that, overwhelmingly, when push comes to shove working mothers will be the ones who want time-off at short notice, can't attend team events (dinners etc for the soft networking) etc etc.
We don't like it, it's not right but the "work as though you don't have a family, parent as though you don't have a job" is what applies here. As an employer, my assumption is that when I'm interviewing someone who has replied to a vacancy which outlines the requirements, is that they have checked their qualifications and support system and can provide me with what i need. If I'm not offering flexible working, then i am not offering flexible working - although to get the right candidate i might be willing to negotiate.
Also, OP, you may just have to face facts: you were on a shortlist and someone was better. That happens a lot, don't lose heart, the more you apply, the more interviews you'll get and eventually you'll land something.