It's only my opinion, but there's a world apart between a parent accepting a descendant's suicide and passively (or even actively) contributing to it. Not knowing your situation, cannot judge, but I would start to ask myself what kind of "gift", gesture, memory you want to let behind your act.
Maybe some sorrow, love and understanding can be shared valuably while alive, by opening up about your intentions (only you know)... However, it may increase for your mom the stress from anticipation, not knowing when you'll proceed, and also put her to face possible legal trouble if there's assistance that leaks. It's not more guaranteed that she wants to learn about the details (only you know about her sensitivity and strength to handle this info in the long distance).
If there's a chance that it leads to help, open up
If the goal is purely technical, I would prefer to ask somebody else than close family ...Unless, you're in a very specific situation where there's evidence that no other choice will ever be possible (like long term struggle or incurable disease), known in advance as bound to happen between both of you. Then, be cautious how you help each other and try to apply your own judgement not to take advantage of the sympathy.
In the end, you say very little about your situation in order for people to give custom advice
