When your baby is maximally supported in kneeling, the components that you want to develop are:
Lifting her head in the midline and maintaining it
beginning weight bearing on her elbows
trunk supported up straight
stretching her hips to neutral rotation and beginning weight bearing on her legs
Her tendencies will be:
to arch her head and trunk without control or bend into the surface
to lose head control suddenly and quickly fall into the surface
to not take weight on her elbows
to position her knees wide apart
to be fussy with taking weight on her knees and need a softer surface
Activity: Supported Kneeling at a Sofa Cushion
Select a soft surface to kneel on and then place a 7-inch (18 cm.) sofa cushion on the surface in front of you. Sit on your heels and hold your baby sideways across your lap, facing away from you. Place one of your arms under her arms and your other hand will place her knees together with her hips and knees bent. (fig. 1.18)
Place her in kneeling with knees together in between your knees and then snugly move your knees against hers to stabilize them together. Her buttocks will rest on your thighs so her pelvis is lifted a little (rather than resting on her heels).
Place her elbows on the sofa cushion and hold her upper trunk under her arms, and this will help her prop on her elbows, with her elboes forward of her shoulders (side view) and her elbows in line with her shoulders (fig. 1.19)
With her legs, trunk and arms stabilized, place a toy (or person) in front of her and encourage her to lift her head. At first she will lift her head with bobbing movement, and as she gains strength, she will be able to lift her head and hold it, while looking at the motivator. If she lifts her head too far, then lean your trunk forward to prevent her from tilting her head back.