Early retirement. is this possible!

Nebulous2

You have a significant amount of capital for 51, but retiring that early increases some risks as it has to last longer. Your children are also fairly young, so you could have some significant upcoming expenses for university etc. 

As far as the hobby business involving your son is concerned, my background is care, and I have known several people develop similar businesses on a self-employed basis. Eggs, discos and market gardens are ones I have known fairly well, and had some experience in supporting. It will be tough to get an income for two of you from that, but getting some income for your son would certainly be possible. Could your partner not do some of that work - as a step up from their current role - with you possibly coming in at a later date, giving time to increase your pension pot and decrease the years you need to fund? 

Kim1965

What are the chances of your eldest going to Uni? You could be supporting children until your 59 yrs old. Potentially very expensive.