'Grow' , when you are talking about children, is intransitive verb.
Children grow. Children grow up.
But you can't 'grow' children in the way that you can grow plants.
The transitive verb is to 'raise' (more common in US English) or to 'bring up' (more common in GB English). So you could say, for example 'Bringing children up isn't easy'.
The only time you'd use the phrase 'growing children' is if the 'growing' were a present participle rather than a gerund. For example:
With three growing children in the house, I spend a fortune on food!