6 months and we did baby-led weaning. It's not really what you asked about, but if she's finishing every bottle, you might consider offering her more bottles now rather than thinking about weaning. At 3 months, my daughter (who was small - 25th centile at birth) was having 8 bottle a day. She didn't drop down to only 5 bottles until 9 months. They really do need to eat lots and often, so if she's finishing all her bottles, I'd squeeze in a few more bottles now while you don't have to worry about solids. Unless she's truly obese and there is a real concern about her weight (usually due to genetic conditions or other congenital issues), there's no reason to worry you might be overfeeding her if she's happy to take it. They need to eat often throughout the day and night at that age. Our HV advice was that we should offer her enough milk so that she left some unfinished about half the time and drained the bottle the other half of the time, in which case, I'd try 8-9 oz per bottle or preferably add in an extra bottle or so during the day.