In Jain Dharma, this is not automatically a sin, but it is generally best to maintain shyness, modesty, and proper boundaries.

If you are young, dependent on your mother, or need help for safety or practical reasons, bathing with your mother is not considered a bad intention. Jain ethics look strongly at bhav — the inner intention — not just the outer act.

Still, if possible, the better practice is:

• to bathe privately
• to preserve maryada and cleanliness
• to reduce attachment and unnecessary dependence as you grow older

So, with a pure intention and necessity, it is not a sin. But in Jain life, one should gradually learn self-reliance and proper personal boundaries.