Hi Karina - great to hear from you! Hope all is well with you and the family, and with your furkids of course.
Megan, there is no need to damp down your hay, as long as it is reasonably soft and leafy Laney will be fine. Also Laney is getting plenty of exercise - lots of walking in your large paddock whilst grazing. Even if your grass is not that good at least she has access to it and it really wont be very long now before the Spring growth starts to appear.
You could add soaked sugar beet to her feed - just a little at a time if she hasn't had it before as it often takes them a little while to like the taste. BUT be sure to stop the sugar beet once the foal is born if there is any chance the foal might get at Laney's feed bowl - sugar beet is not good for very young foals. You will be increasing Laney's food slowly as she gets nearer to foaling, and once she has foaled you can push it up a little more to replace the sugar beet. Also from now on make sure that when she is in her stable overnight, she has her hay ad lib as she needs to be able to graze throughout the night on the hay, just as she would be doing if she was outside eating grass.
For optimum wellbeing horses need to 'graze' 20-21 hours out of the 24 and they dont 'over eat'! They get fat due to the 'quality' of what they are eating - too much lush grass or hard feed - PLUS lack of exercise. Horses are made to cover long distances either moving slowly as they graze or travelling several miles at speed if startled or frightened. Stallions use energy covering the mares and keeping watch over the herd. Youngsters race around playing. The mares use up most of the goodness in their food by carrying and feeding their foals.
Of course most of us cannot keep their horses under the above regime, even if we wanted to, but it doesn't hurt to remember the general rules of 'trickle' feeding plus as much space and freedom as we can give.
So remember plenty of hay for Laney at night and split her other feeds into at least 3 per day as you increase the amount/add sugar beet etc. Dont worry if she gains a little weight, she is 'feeding' a foal who is now growing fast, plus she needs to make milk for the foal, plus she need to build her own 'strength' for the actual act of foaling. then when all those things are done, she has got to provide food for her new baby for several months after it is born. She's a walking miracle!!