I went there with my little Charlotte on the National Day holiday. It's a nice place. Easy to reach, either by minibus or bus from Choi Hung. Has carparks. Not far to walk from the drop-off points.
There is plenty of grassland for your baby to walk. Besides, there are a couple of exhibition hall and areas that educate the public to love the nature. There is also a nice place with tables for picnic too. You can even bring along your dogs too!