Make her a 'Mommy Craft Bag'
Use a plain tote (she can paint on this later if she wants to) add some fabric paint or some permanent markers/paint pens (basic colors are fine) add a few onesies in white, yellow & green for her to decorate for baby. Add a plain adult T shirt in a size larger than she normally (pre-pregnancy) wears to paint for herself. Find some paint patterns online (free ones) & print them for her to use (maybe some baby ones & mommy to be ones). Dont forget a fabric pencil. Grab one of the 'make your own teddy bear' kits & add that for her to make babies first teddy bear.
You can grab cheap onesies & a plain T shirt at the dollar store or Gabe's, and WalMart carries the make a teddies for about $15.00 A set of paint pens is only $10.00 there.
And Wallah....You have an awesome gift for very little money.