Rooney, who is mother to three-year-old Zander and five-month-old Alexa, opened up about how difficult she is finding motherhood.
Taking to Instagram the 35-year-old Olympian wrote, 'I am struggling to get my groove back post the arrival of bub #2 in more ways that one.
'I find the days at home with #lexilevett monotonous yet the days I work I miss her like crazy.
'Head all over the shop, rocking the 'Mum guilt' like nobody's business & exhausted with the constant juggling act of life with a couple of kids..but love them so much I feel my heart could explore!'
Giaan finished, 'Makes me realise how much pressure we put on oureslves to try & get it all 'right', whatever that is?!?!'
The post was quickly flooded with comments of support, and other mother's sharing that 'mum guilt' is totally normal!
'So true, & along the way you have raised an intelligent, cheeky, curious little lady who will one day realise what a rockstar her Mum actually is!!!' one commenter wrote.
'I'd like to thank you for that and for acknowledging that it isnt easy and for thanking those in your life that are your leaning post. Dont be too hard on yourself you are doing a fabulous job,' another follower added.
Well done Giaan - thank you for sharing!