Hello there sorry for your loss Cottage sounds like a lovely idea - something fun with your DS during the day then a come dine with me style dinner where people prepare something for each course maybe Even murder mystery dress up perhaps?
I'd be tempted to find somewhere to go that has happy memories if your dad attached if you feel it would be appropriate. Maybe somewhere you had a happy childhood family holiday or where your parents went on honeymoon if your mum could share memories with you. You'll probably be thinking of your dad at that time, do why not have some happy memories triggered by where you are rather than go somewhere he never went?
Next year I will be 30 and my mum will be 60 - within 4 days of each other. This is a week we have been looking forward to for years, and we had always intended to have a party. However, this summer we lost my dad very suddenly so this no longer seems appropriate. I also want to be able to include my son in any celebrations - he will be 18 months old by then.
My only idea at the moment is to rent a cottage for a weekend/a week but it seems a bit boring unless I can think of things to do/activities/games?
Anyone else been in a similar situation or have any other suggestions for me? I am an only child and I really want mum to enjoy her 60th despite my dad not being there.