Some years ago I watched some minutes of a very interesting movie on TV but I didn't finish it and I only remember part of the plot.

There was this family who had lost a young child (2 parents, 2 children alive), and the mother was in complete denial, to the point she acted as if her dead child was alive: she set the table for 5, she spoke to and about her dead child as if she/he was really there, etc; and her family played along because they feared for her mental health.

I think they hire a nanny or a live-in domestic employee and the husband has to explain her how his wife acts like their child is still alive and the woman has to play along for the job. I think his woman was the main character and was going to try and help the wife.

I have no idea how the story develops from there, nor do I remember the actors.

Reunion (http://www.imdb.com/title/tt0110981/reference)?

No, I don't think it's that one. The dead child isn't a ghost, just the mother's imagination. But thanks for your cooperation. :)

Invisible Child (1999 TV movie)
Starring Rita Wilson, Victor Garber, Tushka Bergen
IMDb synopsis:
A woman with two children believes she has three and her husband and oldest daughter play along with her to keep her balanced (or as close to balanced that a woman with an invisible child can be). However, when the family hires a new nanny, it is all just too much for her and she starts to talk.

Invisible Child (TV Movie 1999) - IMDb (http://www.imdb.com/title/tt0172606/)

Yes, that's the one! Thank you so much!

Yes, that's the one!! Thank you so much!!

You're welcome! I've seen it on Lifetime, just once, but it is memorable.