opinion: second baby?

Meredith • Mother to my rainbow baby girl 10/21/16 and 1 on the way due 1/4/19 🌈🌈
Thinking about the future... little one- our first- is 6 mo old and we would like to have another at some point. Pros/cons of waiting until baby is older versus having them closer together? I'll be 34 in May if that's relevant to anyone's decision making ;-)