Your mother is being completely honest with you.
It is not easy raising children or being married, she is trying to ensure you go into both with your eyes wide open. I would say she loves you very very much, but maybe she felt alone and struggled alot in the earlier day and wants better for you.
I have 2 dds, and I have been truthful with them. Once you have children your life will never ever be the same, I have explained the enormous responsibilities of bringing life into the world, I have asked them to think about how they will manage alone financially, emotionally if they found themselves separated or divorced with children that this needs thinking through well before the arrival of children. I have also explained that love is all well and good but it won't pay the bills, they need to think carefully before marrying anyone that is not together emotionally/professionally/financially etc. They both have self worth, and this is extremely important when it comes to making life decisions. As it is they can care for themselves easily, I will be encouraging total independence both travelling and living alone, learning to manage their lives properly.
So I disagree with other posts to ignore your mother, it is your life and you get to make every decision for your yourself 100% of course, but being fully informed about the REALITY versus some of the myths will ensure, in my view, that you do not fall into motherhood or marriage by accident/mistake is good advice.
If you are entering marriage it needs to be done on a purely equal basis. All housework/cooking/mental load automatically divided up from the very beginning.
Before you start having children work out 50/50 childcare arrangements, and don't allow the expectation that your professional work will be automatically be sacrificed.
Ensure you have your finances worked out in a way that does not depend on you staying married if you are unhappy, from the very beginning.
Do not settle for the kind of man that will drain you dry in any area of life, you are better off on your own. He needs to be an asset to your life or he isn't worth having.
Keep hold of your own identity/dreams and aims whatever happens, you lose a sense of these, then antidepressants won't be far behind.
Look op, having children is extremely hard work - and extremely rewarding in equal measure. When the time comes, if it comes and you decide to go for it, do so from a place of knowledge, care and on your own terms.