My three are 11, 9 and 4. Boy, boy, girl. DD is my second husbands first biological child.
DH was keen on four but i had multiple miscarriages before successfully carrying DD and felt a fourth would be too much.
The family dynamic works well but there are all sorts of little compromises with more children and a bigger age range.
Silly things like at Alton Towers DD wants cbeebies land and DS2 wants to be on the smiler.
Three room hotel rooms can be quite pricy and once you're beyond travel cot stage five in a travel lodge room is less of an option.
Free child/ kids eat free are typically one per paying adult and often the third has to be paid for at full adult rate.
DS1 and DD want cbeebies on the TV (DS1 is Autistic and has some areas of significant immaturity) DS2 wants CBBC.
We drive a 7 seater because DS1 can't sit near the others, he has boundary issues and we can get a friend or two in the car.
I have three DC at three different schools, its a headache. Next year it will be three at 2 schools then possibly go back to 3 at 3 if DD (autistic traits under investigation) doesn't cope in mainstream with DS2.
Due to ages and the Autism element own space is very important and so we have created own bedrooms for the children by carving up one room to make two small ones.
Giving children personal time takes effort with one more so with two and even more so with three. It eats into what was my personal time and being a mum is a bigger chunk of who I now am than I'd originally planned. This may be a personal failing/ partially having an additional needs child thing and not a three children thing. I hope that when DD starts school I can carve out a little time for finding me again.
They all play together really well. Minecraft works incredibly well across the ages and DD has a controller feels shes joining in with her big brothers. Games like mario kart work well too. They play as 2's as well. The boys have certain activities, DS1 and DD do varies games and DS2 and DD are generally very silly together.
I in no way regret having three. Its a completely illogical thing but very very rewarding.
I have two arms and one lap so we can easily snuggle up whilst i read bedtime stories.