How soon is to soon

Ashley
I have an 11 month old son and I think we should start trying for a girl. I Dont want to wait 9 years before I have another one. Let me explain I have a 9 year old that turns 10 next week and I have had a 2 miscarriages, 1 etopic ,2 live births , and a baby at 20 weeks that didn't make it I only have my 10 year old and 11 month old and really want to start trying for a little girl so please help me by letting me know when is the best time to start trying