I'm not Suzanne, but I'll offer my 2 cents worth. 

 If separating her for those hours give you enough milk for your needs and does not cause scours in the calves than that's what I would stick with.  Cows like schedules so you want to keep your milking time close to the same time each day.  We aim for within a half hour (we've gone as far out as an hour) of our set times each day.  Scours can kill a calf so be careful of letting them have too much milk.  With having two calves drinking off of mama you may be okay.  My newest calf is about 5 weeks old.  He couldn't handle being with mama most of the time at this age. He'd drink way too much of what she produces. So I milk 2x a day and leave one teat each time for little Stew.   Also, the older the calves get, the more milk they can handle.

The calves do not need feed, but you can give them a small handful each time before you let them go to mama.  (You can buy calf feed.  We use just plain ole sweet feed.)  This will help teach them that you're their friend.    Makes things easier down the road if they will let you mess with them.  They should start to eat grass soon.  I know our little Stew has been eating bits of grass this past week.

Yes, Miss Judy, that is correct. The cow generally adjusts to the demands.

Why I said she may be okay milking just once a day and letting the calves be at mama the rest of the time is because there are two calves.  If there was just one calf, I'd say that as young as it is that much milk from mama would definitely be too much.  It may be too much for the two calves.  She'll have to watch their poop.

She probably won't get as much milk at milking time doing it the way she is now instead of milking twice a day and then letting the calves have their share.  However, if she's getting enough milk for her needs and the calves are healthy then everyone is content.

Was the person milking at the same time as the calves being with mama all the time?  Also, remember the first few days is just colostrum.  It takes a few days for the milk to come in.  As long as the calves don't get scours than the only thing you need to worry about is if you get all the milk that you need.  If you're wanting more milk, than you'll have to separate the calves from mama more.

I separate Stew all the time except after we milk.  We milk once in the morning and once in the evening, between 7 and 8 each time.  We milk out Mama Pearl all but one teat.  We don't leave the same teat but rotate around.  We let Stew drink and then check to make sure Mama Pearl is milked out afterwards  Once Stew is done, we separate him out into his stall and calf yard.

I understand about being in love with her already.  My favorite cow is the one we got last year.  She was our first.  Her name is Bessie and she's a Jersey. She is due to calf anytime.  Buttercup was her first calf and she's here on the farm too.   We got Pearl this year, and we're getting used to each other.  She's a Guernsey.  She's not as ornery as I was led to believe, but that may be because we're using a milking machine with her (thank you, Suzanne!!!!) instead of hand milking.

It can definitely be overwhelming at times.  At the same time, it's a wonderful thing.

LK brings up a very good point.  I am sorry that I did not make it clear.  I would not give the calf feed without letting it eat grass.  We generally only give our cows feed at milking time or as a treat.  They eat grass and then have hay during the winter.  I am giving them some alfalfa cubes at treat time this year as our grass and hay is not the best. 

Buttercup, Bessie's calf from last year, will drink from Bessie every chance she gets!  Buttercup was separated for months before going to visit at Suzanne's and then separated again when she came home.  Yet she still tries to drink from Bessie whenever they are together!  I'm hoping that when Bessie and the Buttercup have new calves that Buttercup will quit.  It makes it a challenge to keep them apart. Our grazing area is split in half but I'd rather have them all together so that the fields have a break.