I don't see why you couldn't have them both at the same property now, but I would keep them separate. My colt has been weaned for about 2 and a half months and he still has to be separated from mom because when we tried to put them in together, he was still trying to nurse. He is not "attached" to her or she to him - like they used to be, but he must have just though, "oh, my special meal is back"
It is a bummer that he keeps escaping our electric, so he doesn't get to stay out with all the big boys in the big field. He has to stay with the pony in the solid pen.

The two little shrimps are cute together though.