So, in my novel, I have a mother-type character that's a little young to be a mom (am planning on having her have a child she's planning on saving). So, I wanted to know your opinions on how far I can push the bounds realistically on the "mother" character.
I'd say that the qualities of motherly characters aren't inherently tied to being "able to bear children" or "old enough to be a mother".
Aside from the fact that (as other noted) people used to make offspring earlier in the past (mainly due to culture and shorter lifespan), I'd say this:
Most key components of "being motherly" aren't related with the physical act of giving birth
Being motherly boils down to:
- being caring
- being compassionate
- being kind
- being reassuring
- being empathetic (aka, being aware of other people emotions and act accordingly)
- being good around children
Now all those things don't necessarily imply that the character in question has given birth. You can write a perfectly believable baby-sitter coming off as motherly just because she's kind, she's good at treating the children, and enjoys taking care of other people needs.
Some of the people I know exhibited those traits well before being of the legal (or even biological) age required to bear children. So while it's not a general rule (not every girl is motherly by default, of course) it's not uncommon. From a non-gendered view, think about how children of 8-9 years can emulate their parents behaviour when dealing with younger siblings.
So, unless you need your character to have a "motherly figure", which would at least require some growth since it's a physical-related trait, she can show those qualities regardless of having a child or not.
Age would come into play since a bit of mental and emotional maturity would be needed to show those traits in a consistent way, all the time. Smaller children are more prone to being at least a little egoistic, and that doesn't really work well with all the caring, empathetic part. Also to be "reassuring" you have somehow to be credible, instead of being easily scared (as again, younger children are).
In the end, I think that a nine year old can exhibit motherly traits at times, but can't come off consistently as motherly (unless she lives in a society quite different from our modern, first-world one, when children grow more mature faster). A teenager could be a more consistent, all-around motherly character just by natural inclination.
So, all around, Galastel comment wraps it up. Wendy in Peter Pan fits the description.
I would think that any age is ok - I'm thinking of 4 yr old Daisy in Little Men, lol. It would be less about the age and more about the actions. This is the time to do that "show, don't tell" thing. Throw some sentences in that show her tending to others - plucking lint off their clothes as she smooths their sleeves, making sure someone has all they need before leaving. Think of things a loving mother would do (ruffles hair, chucks under a chin, words of encouragement) and have her do these actions to everyone.
If the mother character is the biological mother of the child, very early teens is credible. If she is some girl who wants to care for a child and decides to do so, without any advice or assistance, it can be even younger.
I have a character who was forced into a motherly role at twelve, but she had help from others.
In the past a fifteen year old girl would be a wife and mother.
In 'Romeo and Juliet' Juliet is thirteen and her father initially says she is too young to marry. He then changes his mind. Her mother had been about the same age when she was married and had Juliet.