We stayed at Ana’s place in Caiscais for two weeks. We were four people and had plenty of space. Could be 5 people max if you include the sofa (a person up to 180 cm could fit). Beds are comfy and bedrooms have closets to put away your things. There’s also a nice fire place for days when you want to chill at home.
The apartment is 10 minutes walk from the train station and the city centre with restaurants. It took less than an hour door-to-door to central Lisbon. There are plenty of beaches along the coastline of Caiscais and along Estoril coast that we recommend.
All in all a good apartment with close proximity to many things. I definitely recommend it for families or groups.