Aw ang ganda ng plan mo! Honestly, with a 6-month-old, I'd suggest going early in the morning para hindi sobrang init at busy, tapos maybe just focus on the main attractions na hindi too far from the entrance so you're not walking around too much with the baby. One of my mum friends brought her kids around that age and she said the 4-year-old loved the animal shows, but the heat was intense kaya prepare lots of water, snacks, at maybe a light stroller cover para sa baby. Definitely doable, just take it easy lang and don't pressure yourself to see everything in one trip!