Second child?

My husband and I are really trying to make the decision about wanting a second child or not. Our daughter is only 4 months old, but if we are going to go for it we would want to start trying when she’s close to a year! We want another because both of us are only children, and our daughter will have no siblings, cousins, aunts, uncles, etc. We hate the thought of her being all alone, BUT we are also just really on the fence of another child! We loved being only children 😂 so moms with multiples, when and how did you decide that was the right choice for your family? To have another. Or moms with only one, are you happy you made the choice to have an only child ?!