No, if they use their own kids they are petty bourgeoisie, I have slightly elaborated in another answer, 19th century family hits different. But anyway, same also kinda works in 21st century, business run by husband and wife, if they don’t have completely separate financial accounts where one person determines price of labor of another, they are still petit bourgeoisie as a family unit. And yes, as soon as they hire someone outside, they transition into bourgeoisie.

If one where to make finer distinctions, think of it more like a star scale with three prongs, there three axis, exploited, owning their own means of production and exploits others (owning others’ means of production). So a worker maintains same scale of being exploited, while their 401k slowly grows their prong of owning others means of production. Meanwhile petit bourgeois sits firmly on 0 on being exploited, but also until success 0 on exploits others. While haute bourgeois sits firmly on exploits others and doing jack shit, so 0 on both, unless they also doing some failson work. They could also be loaded doctor who is exploited by medical system, but at the same time their pay scale rapidly brings them closer to bourgeoisie, while they are being exploited for 1/3 of their life, they are exploiting back via diffuse capital ownership, but that’s neither here nor there