big cycle this weekend...

gloryofthis

...my partner and i are taking out little girl to visit my mum, we have decided to cycle to the boat instead of getting the bus and train, its a 40 mile cycle and is mostly a national cycle path. then after staying at mums friday night and saturday we will do the same cycle back. 40 miles isn't a lot to my partner who is a keen cyclist but my longest cycles are 5 miles to my grans sit around for 2 hours then 5 miles home. does anyone have any advice for a big cycle? really starting to worry i'm not gonna manage it and i really want to because everyone i've told so far has responded with "oh.... thats a really big cycle...you know...for someone your size.... are you sure you're up for it?"

so yeah any practical tips/ helpful hints?

much appreciated
bev xx