How did you decide to have another child?

Max
I'm a FTM and always thought I would have one child and that's it, but now that I have one...all the parent worries are in full force. The biggest one, who will she have when she no longer has me😔. This has got me seriously thinking about her having a sibling so they have each other...I'm in no position right now for a second child BUT I'm getting older and really I can find ways to provide I just want her to always have someone. 
How did you ladies decide on having more children? What was your reason?