Does the soul age?
Soul age or is it constant? Yes, the soul doesn't age that avikaryo yamunchate in 2.25 the Bhagavad Gita says that avikarya does not undergo the changes that the body undergoes specifically.
So the soul is eternal the soul is indestructible the soul is unchangeable and actually our desire for stability we all want something to be unchanging in our life we want some security in our life when the whole world around us is changing now where does our desire for continuity come from? Why do we want continuity? If we were simply the products of the world around us, if we are simply material products then why would we have a desire for something that is just not present in the world? The only thing constant in the world is change. That's the only constant thing. So Adhibhutam Ksharobhavah, Krishna says in the Bhagavad Gita in 8.3 that this material world is characterized by change.
So when everything is changing why do we have a desire to have something unchanging in our life? That is because we at our core are unchanging we do not desire to grow old or get diseased or die because the soul is not soul never gets old gets diseased or die and we are projecting our identity onto the body and that's why whatever is natural to us as a soul we are trying to get it at the level of the body but the body will grow old, get diseased and die, nobody can stop that. However if we realize our spiritual identity then we will realize how we are actually eternal how we are how we are inexhaustible how we never grow old. Does this answer your question?