First Time Heifer calved and is now super depressed/ill

Hello all, I have been observing this heifer now cow since she gave birth on the 11th of May. Labour was pretty rough, we had to pull the calf. It was a large bull calf. Once we pulled it she stood right up and did her thing. I kept them in confinement just to be sure they pair up. Day 1 and 2 all seemed normal. I saw the placenta on the floor, she was feeding herself and nursing her calf. Day 3 I noticed she was laying a lot and seemed sick. Doc said maybe some of the placenta got stuck. So I gave her his prescribed amount of Oxyvet. Day 4 and 5 she looked great again. The antibiotic is a 3 day so I decided to give her the second dose on Day 6 like vet said. Then I kicked her out of the small nursery pen to rejoin the herd as all was looking good.

Since she has been out, I am struggling to figure out what the issue is. She constantly lays by herself away from the herd. And for long periods of time. She also leaves the calf a long ways away from her. I can come up and take the calf she wouldn't be bothered by it at all. I am used to my other momma cows who yes will leave the calf in the grass and go feed. But they circle back every hour or less. And if I walk up to there calf they are on me like white on rice. I do see her eventually go and feed her calf, but not nearly as often as she should be. I typically see a morning feeding, then likely won't see another one until like evening. The calf himself is now 8 days old, seems plump. He doesn't seem skinny. So he must be getting milk. But I don't see nearly as much mobility out of him vs a heifer calf born the same day who runs around the pasture all day. He lays pretty much all day too. Gets up and cries for mom, she doesn't come and just lays back down. Eventually when she feels like it she will come over to feed him.

This cow is actually one of my most friendliest cows. Always comes to me when I am outside. She does not bother getting up to see even when I carry out grain.

Do you think she is still sick? What could be causing it? Is this some sort of post partem depression? Or is she just not a great momma and wants to avoid her duties? Expecting a lot of rain this weekend so I was hoping she would do a better job and be closer before I let her just leave him out in the rain. Any help would be appreciated.