Isabel Roloff’s emotional tweet about watching her 7-month-old son Mateo ‘grow up’ has Little People followers in tears.

Fans of Little People, Big World are in tears after Isabel Roloff posted a poignant message about having to watch her seven-month-old son Mateo “grow up.”

Isabel, 26, wrote on Instagram about how every mother has a “unique type of sadness.”

Mateo was wearing a wool onesie when the former LPBW star uploaded a black-and-white photo of him.

The camera avoided the toddler’s face and concentrated on how he was attempting to close his hand.