The 28-year-old singer recently revealed that she would like a second child with her long-term partner Simon Konecki - with whom she already shares four-year-old son Angelo - once her tour has finished, and sources now claim the 'Hello' hitmaker made her decision after seeing Robbie's growing brood.
Adele has been spending time with the part-time Take That singer, 42, his wife Ayda Field, 37, and their two children, daughter Teddy, four, and two-year-old Charlton family, which has made the 'Someone Like You' singer ''very broody''.
A source told The Sun newspaper: ''Adele has got really close to Robbie out in LA.
''She and Simon were going on double dates with him and Ayda before her tour kicked off in the US, and spending time with Charlton has made her very broody.
''As a result, she started thinking seriously about giving Angelo a little brother or sister and brought it up with Simon.''
However, Adele is said to be focused on weighing up whether to send her son Angelo to school in the US or the UK before she can think about her next child.
The source added: ''Adele is an only child and her mum threw her into social groups so she always had mates -- that's where she got her huge personality from.
''But it is more difficult for her to do the same with Angelo due to her fame, so she thinks a sibling will be good for him.
''Now she is just trying to decide whether to school Angelo in the UK or in the US. It's a huge decision that she is having to weigh up.''
The 'Rolling in the Deep' musician first told fans she was thinking of having another baby in October, when she told audiences in Nashville, Tennessee, that her womb was ''starting to ache''.
She said: ''I'm starting to get very emotional about it because I feel like once they turn four, they're not really your actual baby anymore.
''So my womb is starting to ache a little bit. It's like, 'Baby, baby, baby. Need a baby, need a baby'. I'm not pregnant. I won't get pregnant until the end of the tour.''