If she is only in for the one day, then don't rush up to the hospital, but let them know you'd like to come if poss.
When baby is at home, ring first to ask if its convenient to visit and if they put you off for a day or so don't despair. When you DO go, ring up and ask if they want anything picking up from the shops etc on your way.
Don't offer advice on anything unless asked 
just have a lovely cuddle and arrive with shopping and goodies for baby.
Suggest that dil has a sleep or snoozes with baby while you make tea/washup/hoover etc for her.
All these things, my friend did for me on a day that involved her taking a day off work to drive 100 miles to come and see me and my 2 week old baby (post section).
My mil? Barged into the hospital the evening visiting on the day I'd had a section at 2pm. I was naked under the sheet and trying to bf a 9lb baby that hurt my scar everytime I picked him up. My wee bag was still attached by catheter and very obvious to anyone coming near the bed. The nurses came at regular intervals to take away bloodied pads that I had under my bum as I was to stay in bed with catheter attached, for 24 hours. I told dp to ask them to come the next eve as my parents were coming the next day. I didn't even want my own parents to see me in that state. I also still had a drip in as I'd been nil by mouth since 6am. Mil and fil drove over for evening visiting, just as I was being given some soup and toast.
Now I am not one to deny any grandparent a cuddle with a new baby. But mil sat on the end of the bed cuddling ds2 WHILE I VOMITED MY SOUP INTO A PAPIER MACHE BOWL. Neither her nor fil helped me to sit up so that I could actually get it all into the bowl and not all over the bed. No they carried on with the photos then when I'd finished and was sobbing all over the nurse helping to clean me up said 'have you finished now ugh good job I had baby so you weren't sick on him' !!!