I'm a Lytham girl,** and there's loads of nice places to eat in the town. Do you know the area at all?
Down the main shopping street, and particularly leading up to the market square piazza, there are several good family-friendly Italians and Med restaurants, Bosco, Java, Portofino, Zest, Ego.
Two excellent fish & chip restaurants, Seniors and Whelens. The County Pub has a great pizza menu, The Queens. near the Windmill, lovely pub food, and there are tons of cafes for during the day (Lytham Kitchen. best. ever!!)
Lytham Hall is open to the public on certain days and the grounds are open at weekends. Not that much to do but lots of running space.
Weather permitting, there's Lowther Gardens just on the Green, great for running around with a new outdoor play area and a no-frills cafe.
Further towards Blackpool, there's the usual penny arcades, rides, piers, etc; dungeons probably bit too scary!
The prom has had a recent facelift and though Blackpool is never going to be anything other than it is, it's good fun just walking along the prom, or catching a tram (there's a lovely newish tapas/cafe called the Beach House just opposite the Tower.)
St Annes Pier and arcades are a little more sedate if you can't face the Blackpool ones!
Ribby Hall (5 mlles inland from Lytham) is open to non-residents.
Big indoor pool, indoor play area, Starbucks, Pizza place, table tennis, etc. good outdoor play area, several restaurants, it's ideal if the weather's bad.