You are likely not checking too much. Kind of at the stage waiting for the big change. Very likely she’s in foal with that much udder development, foal belly, and movement. Late term the foal won’t be moving as much because there is not much room. I check my girls a minimum of 2x a day until they are close. Then it may be a couple hrs between checks. And they are on camera constantly once they start getting in the 300 day range. It’s hard waiting to see big change. But it will come. If you can, you may try taking pics first thing in the morning. That will give you an indication of how big her udder really is. By the time you take those pics she has been active all day and her udder will shrink. When she gets really close, it will stop shrinking during the day. If you can’t that’s fine, just know her udder is likely actually larger than those pics show.