As I pointed out in my previous post she seems to be seriously under equipped for use in the sea. Even for day fishing you will NEED an anchor & cable plus vhf, flares etc. My guess is that she has been used for picnics on the river.
It's commendable that you want to go out and experience nature and the sea with the family, but (in an admittedly harsh comparison), it'd be like taking the family into the outback in a Morris Ital.
I agree with apollo - just have a professional check it over, especially all the ancillary equipment that goes with the engine - cooling, pulleys, drives etc.