I let my last fresh nurse cow go about 3-4 days with her calf on her before it got to the point I decided she really needed to be milked out as the calf wasn't drinking enough -- and even after I brought down two more calves to put on the cow, well, I could see I had a problem. LOL. Ended up trading that cow temporarily for one that gave a lot less milk (5 gallons/day for 4 calves) and sent my cow to my boss's dairy.
If you leave a cow unmilked (or delay milking) you are asking for mastitis. So once the cow has calved and the calf has nursed and wobbles away what do you do? Do you leave the rest of the milk in her or milk her dry?
If I remember right, you said on the other post this will be her third calf. Given that and then that she's going to be milking fairly heavy, I would definetely delay milking her out completely for a few days. Let the calf take what he wants but don't milk her out yourself yet. Middle-aged heavy-milking cows have a tendency to come down with a metabolic condition called "milk fever" - not truly a fever; it's a calcium deficiency caused by the start of lactation and left untreated it can be fatal. You'll know if you're dealing with it as the cow will be down and unable to get up. BUT- it can be usually be prevented by a "dry cow diet", administration of calcium after calving,
or incomplete milking following calving.
I didn't have any milk fever problems with my last nurse cow - and I do think it was due to my not milking her out and just leaving the calf with her, and then only milking her dry once a day for several days after that. Had that cow palpated 30 days after calving and she was already "open, clean, and cycling".
That's a sign of a smooth transition period from dry cow to lactating cow.
I'm not 100% certain, but, I'm beginning to suspect that perhaps not milking a cow out isn't a huge deal and doesn't necessarily cause mastitis - but, if the cow already has a subclinical infection going on (no visible signs in milk or appearance of udder) that skipping a milking when she's used to a certain (say 2x/day) schedule CAN cause the infection to change to clinical. Like I said, not 100% certain and no proof, but that's what I've begun to think based on some cases that I've seen.
We had one cow here in the milking herd that slipped on the ice at 165 days of pregnancy. Pulled some muscles or did something serious to her back end, and she was very unsteady, shaky, and fell down numerous times over the next day or so. If she'd been closer to 220 days (dry off time) we would have simply dried her off and put her out to pasture so she wouldn't have had any more problems. As it was, we put a pair of hobbles on her back legs for support, and as her milk production declined dramatically, we only milked her once every other day or once every 3-4 days, depending on when she looked full. Did that for 2 months, and never once did she show up with clinical signs of mastitis. *shrug*
Generally fresh cows (first week or so) I don't worry too much about being incompletely milked out -- but a cow that's been in milk for some time (month or more) and is accustomed to being completely milked dry at each milking I would not want to leave incompletely milked out. Mid-lactation heavy milkers I worry about more than mid-lactation light milkers. (That's why I hate putting brand new calves on a heavy milking nurse cow in the middle of her lactation. lol.) You should be fine with your fresh cow.