Following Rituals and Customs

You might want to put it this way - YOu are elder (person) so amma you do the lamp lighting thing you can say when she comes. So that way she might even feel good too and let her do what she wants.

 

Dear OP

Every one has different thoughts and each one's opinions also differs,

for me lighting lamp, incense sticks ,decorating the god photo's with flowers and closing my eyes for a few minutes make's me happy thought the day. Though I don't spend hours in the pooja room , even spending a few moments makes me happy, I feel positive vibes coming through.... i feel relaxed even with my simple pooja...

may be you MIL also feels the same.... JMO

 

Ramvenks
Dear,
Life is made of adjustments.
From birth we adjust to environment as contrasted to mother's womb.
But how we do it smoothly is our success.

In your case since you live only in India I don't see much problem with this lighting business.
It is not only for light we are lighting the lamp, but invoke the Fire element Agni as it is supposed to be the symbol of purity and holy.

But it is purely one's belief. This is such a small afjustment. We in Indian custom even show respect to the dil as her right to light the lamp of the house.Just verify to yourself whether it is going against your conviction or your ego that you don't want to be instructed.
In major issues you can take a decision definetely It is your life and house.

Since you say that she lives in village she may not have a say in major issues.

But if it stops with lighting lamp you can tell her that she is free to light and do pooja but not insist in your doing it. From eternity this mil dil problem exists.
Shall I share ajoke It is said that Goddess Lakshmi and Saraswathy do not stay to gether as they are both Mil dil!
My sincere suggestion is any situation deal it with your mind and heart and forget about it Do not ponder If you think you are right be at it at the same time decide whether you can adjust to the situation at hand.
House harmony is worth some adjustment.
Ramaa