Might as well milk her right out on that side.
We don't start separating the calf from the cow until about three or four weeks, from memory, because up until then the calf still isn't up to taking all the cow has between milkings. By the time you reach that stage, you've kept the cow's production up and there's still enough for you and the calf's needs.
This all assumes she has good production throughout her lactation, by breeding as well as feeding. A cow which couldn't even do its own calf well wouldn't be a good candidate. Do you have facilities for weighing your cattle? It would be sensible to monitor the calf's growth rate/weight gain if you're in any doubt, but if it's looking healthy and growing well and she has ample milk, all's well.
Back to one of your original questions: she should come back on heat in the usual sort of time to be put back in calf within three months and you can keep milking her up until you need to stop for her to get ready for the next calf. I use a fairly conservative 12 week dry period; the rest of my herd is beginning to show some udder changes by then, so I figure that's time for her to be left to herself as well.
I really enjoy having a housecow, in these days of overly-processed commercial milk.