Probably too late now, youngmumandbump, but you may find some of these ideas useful!
Not sure where you are in Lancashire - my Mum lives near Preston (I was brought up there) and so have been visiting with children since DD1 was a baby. DD1 now (just) 4 and DD2 6 months.
Barton Grange New Garden Centre on A6 at Brock near Garstang excellent. Lots to see (and buy!), lovely changing facilities, highchairs etc. Near canal too so ducks to feed etc.
Cobble Hey - have a look here Lovely gardens, farm animals, cafe in similar area.
Lytham and St Annes always nice near the coast, good shops, cafes and lots to entertain older children.
Low Sizergh Barn shop Lovely food, cows being milked and crafts Good if you're heading towards the Lakes - not far from motorway.
Have also heard very good things about here Bowland Wild Boar Park Hope to try soon!
Hope these are some use - possibly as your baby gets older. Have realised from these how much we look at animals (to placate DD1) and then eat cake!
Afraid DD2 just gets bundled along!