She was pro-choice becasue she was selfish... as a virtue even.

As a philosophy Objectivism emphasizes the main subjects of that field, which necessarily addresses the adult thinker with experience and who can understand abstract principles. It does not ignore children and families, though Ayn Rand did not specialize in child development and did not write about raising children.

In Atlas Shrugged she illustrated in a flashback the early developmental stages of two of the main characters as children growing up, in the form of stylized romantic fiction reduced to essentials. It contrasts the young Dagny and James Taggert in the same household with benevolent parents, showing how the children's different choices within the same environment led to entirely different personalities and character.

The Fountainhead contrasted the independence of college age Howard Roark with second hander Peter Keating.

In Altas Shrugged, well-behaved children in families were mentioned as part of the life the Valley. Ayn Rand said that the purpose of the scenes in the Valley was to illustrate in fiction how the best people interact with each other. Again, that emphasis has to be on mature adults because of its philosophical purpose, but there was a minor reference to children.

Proper raising of children and family relations are of course important in normal life, but are not a main branch of philosophy and could not be a primary emphasis in novels emphasizing the role of the mind and independence in adult lives and the course of a culture.

On more general family life, in addition to the Taggert household Ayn Rand described the adult Rearden family, contrasting Hank Rearden with his brother and his ill-chosen wife. The Rearden family descriptions show that 'family' is not a primary, with a duty to bear an impossible burden (Hank Rearden's mistake): If you have a bad family, whether born into it or through a bad choice of marriage, get out. Romantic love between rational individuals is the basis and reason for a proper nuclear family. Obligations to and desire to associate with family members in general depends on who and what they are as individuals. Leonard Peikoff discussed this in some of his podcasts.

In non fiction Ayn Rand wrote important articles on formation of a philosophical outlook. "Philosophy and Sense Life" is reprinted in her anthology The Romantic Manifesto https://www.amazon.com/Romantic-Manif...

“The Comprachicos” provides a moving analysis of how children are damaged by the influence of bad education promoted under bad standards -- in her anthology The New Left: The Anti-Industrial Revolution, later reissued as The Return of the Primitive: The Anti-Industrial Revolution. https://www.amazon.com/Return-Primiti...

She also wrote about the importance of freedom of choice in education in "Tax Credits for Education” in The Ayn Rand Letter.

Leonard Peikoff gave lectures on education of children, reissued in book form as Teaching Johnny to Think: A Philosophy of Education Based on the Principles of Ayn Rand's Objectivism. https://www.amazon.com/Teaching-Johnn...

A child is an obligation and a joy that an Objectivist chooses. Maybe that’s why Rand was “pro-choice”.

This is a great question. Do you have any insights as to how to enjoin kids to begin an enthusiastic participation in this?

I'll suggest this: Awareness, participation, insight and commitment as a starting process.

I've begun teaching the kids. Beginning with self evident inquiry. What are you? I do this with adults too.
The conditioned response is overwhelmingly; I'm a person, slightly less, a human. What are you simpler than that? I'm an animal / mammal. simpler........Life. A leading process. What does all life experience? Comfort / discomfort.

This begins fundamental awareness and participation in Self and the connection to Live or Die as a value base. The kids get this far faster than adults who have to weigh through subjective learning history.

I qualify with: Do not trust me or trust I am telling you the Truth. Think about this and experience it. I will never tell you something in which I cannot take you to the source and have the source repeat (in context). First, I put the burden of objective behavior on myself.....this is why my forehead slopes. Dealing with my developed bias' and acknowledging the behavior, and changing that behavior has been the foremost challenge of my life.

There is no reason that the very young, 6 or 7, cannot begin to experience objective philosophy, excepting the awareness or the bias of parents.......hmmm.

Yes, but the question, I think, is how does an Objectivist relate to children?
(Not, how should children behave?)
Since as you say their survival depends on adults, what are the responsibilities of adults to their own and other children and families?

Children and families make rare appearances in Rand's writing, non-fiction and fiction. There are clues for example in Atlas Shrugged. What I get is not very explicit, maybe from my inadequate study.
If they are not your family, then Galt's Oath applies.
Otherwise, my opinion is that if it is your own family then there is a contract, legal if a spouse, implied if children. The terms of the contract are binding, some of the terms may be expectations of the society (for want of a better word).

Family relationships are covered well. Children not directly but I think it's obvious they are taught to live by objectivist principals.

Could you please expand upon or clarify your question?

There are children in Atlas Shrugged in the Gulch.
So, you could argue that family relations and children are not properly covered, but ignored - no.

What makes you believe objectivism forgets about children and families?