When Will My Child Begin to Draw Realistic Images?

I'm wondering when Maia will begin to draw realistic figures. I feel like the mother of a baby waiting for her child to crawl or take her first steps! 

Here's an interesting site with illustrations (including the two above) showing the natural progression of children's art from the first scribbles to various stages of realistic depictions.

Susan Striker, the author of one of my favorite books on introducing art to kids, Young at Art: Teaching Toddlers Self-Expression, Problem-Solving Skills, and an Appreciation for Art, also talks about the art stages a young child goes through. In her chart on the drawing stages on page 54 of Young at Art, Striker says that from 30-36 months a child, "Names shapes after drawing them. Lines are often connected to enclose shapes," and that from 36-42 months a child, "Tells stories about pictures. Begins mandala experiments; may draw humans."

Maia is 29 months old, so I guess we're approaching possible realism. I'll keep you posted. Maia does occasionally name her scribbles ("these are cookies for Oliver and Leah — chocolate chip cookies and lemon cookies and oatmeal raisin cookies") and maybe by the naming of them I should consider them realistic drawings.

But instead I'm waiting for her to start drawing the mandala and the person with the hands and feet coming out of the head that I've come to expect from my own childhood drawings (my mom saved them!) and from Striker.

Of course, I'm trying to be a good artful parent by not encouraging her to draw a person, but rather understanding that it will come in time when she's ready.  

But here's my question… Why, when we are "allowed" to encourage our child's first steps, are we "not allowed" to urge our child to draw a person?

Why is one labelled helpful encouragement whereas the other might supposedly stunt the child's artistic exploration by moving them out of the scribbling stage prematurely and showing that you value realistic drawings over others? I wouldn't want her to start drawing people just for my approval or to stop drawing altogether out of frustration.

I don't know the answer to my question, but I'll continue to encourage Maia's scribbles while waiting (quietly) for the first sign of realistic drawing.

Any thoughts?