Only 1 child

Any mama's on here have one child and have decided you are good with only one? What are your reasons? I've been debating on ttc#2 for at least a year now and I can't decide. I've made my list of pros and cons and my husband and I have talked about it several times and I just can't decide. My daughter will be 3 in August and if I do have another I don't want them too far apart so I really need to decide. I know no one can make the decision for me..I'm just wondering others' reasons for sticking with one.