You can use the Topeak Mini Dual DGX pump for Presta and Schrader valves. It has an all-aluminum body, pump head and handle, and a built-in pressure gauge.
Description: Swimming vest for children aged 3-6 years or with a body weight of 18 to 30 kg and a chest circumference between 50 and 66 cm. The vest is composed of three inflatable air chambers equipped with secured filling valves (including the collar) and two buckles with an adjustable belt. Warning: The vest is not a lifesaving device, does not fully protect against drowning, for use in water up to a child's shoulders deep.