Mónica also spoke of how much she had loved being pregnant at the same time as her Oscar-winning sister, who is due to give birth to her second child with husband Javier Bardem any day now.
She said: 'It was magical Penelope and I can share this time. She has given me a lot of advice.'
Although she has not confirmed the name of her baby girl, she said her daughter was sleeping well and 'very good'.
The model revealed the truth about her pregnancy on her web based blog for Spanish newspaper El País in January.
She admitted she had taken the decision over fears she wouldn't meet her perfect man in time to start a family.