Does Le Blanc's mirror images created by her legend ability trigger Star Spring?

No, the Reflection token created by LeBlanc's (Deceiver) legend ability does not trigger the ability of Star Spring.

According to the text of Star Spring, its ability triggers only when a player plays a non-token unit. The Reflection token created by LeBlanc's ability is a unit token, so it does not satisfy the condition for Star Spring's trigger.

This interaction is also explicitly addressed in RiftJudge FAQ #10351, which confirms that playing a Reflection unit token using the Deceiver legend's ability does not trigger the ability of Star Spring for this exact reason.