Is there an age cut-off for bringing a child along to confession? What if I keep my confession extremely short and with few words, maybe even spell out the few words? I’m not comfortable leaving the child outside the confessional unattended yet.
No one, child or not, should ever be brought into the confessional with a penitent. The only exception would be a trusted translator needed to facilitate the confession itself. To do so places the burden of the sacramental seal on another person because that person is as bound as the priest not to reveal the contents of the sacramental confession. No child should be burdened with that responsibility, especially one old enough that the parent must spell out words to prevent understanding.
If you cannot leave the child “unattended,” then find a babysitter so you can go to confession. You might even mention the problem to the pastor and ask if he could help moms in the parish coordinate confession times so that they can take turns watching each others’ children during confession.