emerging Native Prairie Grass -- Weeds: should I pull?

I have a small area in my backyard where I have put in native grasses (indian grass, switchgrass, little bluestem & big bluestem) It is coming up slowly, I planted from seed about 8 weeks ago. Now the tallest seedlings are about 3/4 to 1 inch tall.

Problem is there are a number of weeds in the area. Do I pull them, or just leave them and assume the grasses will eventually grow over them and make them go away?

It is a 20 foot by 10 foot area that I had always just let my regular grass grow long, the kids love to catch insects in the area, so I finally bought to some native grass seed, it should be cool once it gets tall..

Sorry, computer locked up, and I hit button twice. My bad. I look like a dork.

Hand weeding's probably the easiest, especially in 200 sq ft. Here's some help with your project: