me and my mother change clothes together in a room private is it a sin no or yes strictest answer possible even if we were naked I know is improper but is it a grave sin as a layperson is it a minor fault

Strict Jain answer: No, it is not a grave sin for a layperson if it is only changing clothes in private with your mother and there is no lust, no sexual intent, and no misconduct.

In Jain ethics, the main fault comes from intention, attachment, and passion. So:

• Accidental or practical nudity while changing clothes is not a major sin by itself.
• If done without any impure thought, it is not a grave karmic offense.
• Still, it is improper from a modesty and restraint point of view, so a Jain householder should avoid such situations when possible.

So the strictest fair judgment is:

• Grave sin: No
• Minor fault / improper conduct: Yes, if avoidable

If there were sexual intent, deliberate exhibition, or impure thoughts, then the karmic fault would be much more serious.