In 2014, the couple welcomed their first child, Mia Grace Tindall, six.
Lena Elizabeth Tindall, two, was born four years later in 2018.
While Zara will often keep a low profile, she sometimes makes appearances with her family.
The expert said the couple could encourage gentle competition to boost the children’s confidence.
They have been seen doing this when engaging in competition with their children.
Jo said: “Zara and Mike Tindall want their daughters to be very competitive and Mike apparently beat his six-year-old when teaching her to surf.
However, the royals seem to challenge their children without knocking their confidence.
Jo explained this can help prepare them for obstacles in the future.
“They are then far more likely to embrace new challenges as they grow and develop and will have better self esteem.”