I wrote this in another thread so figured it wouldn't hurt to send it this way

You're going to want to work her maternal instincts. Mother's tend to be less rational when it comes to her babies. She wants to protect you and she wants you happy.
If your mother sees you pinned under a burning car, she'll run into the fire and lift it off you. Given the circumstances, she may be willing to fuck you if she sees you in the equivalent emotional state.

You want to come on slow, so in case she's not going to be into it, you can back out with minimal damage done to your relationship.
But when she beings to seem open to the idea of broadening your relationship, you're going to want to come on to her fast. The longer you take, the more she has to think about it.
Avoid being vague and unclear. You want to be frank and straight to the point with each step. If you make her try to figure you out, she's going to be contemplating more and more about the situation, and her rational mind will take over and tell her to stop.

Looking ashamed and embarrassed is a good tactic. Make it look like you don't want to feel these feels and you're ashamed of the way your body reacts to her. If it looks like you punished yourself, she'll be more likely to comfort you than scold you.

Obviously alcohol can help. You want to get her tipsy and not drunk.
Just enough for her to lower her inhibitions but not so much that doesn't know who she's talking to

If you manage to get to foreplay, you want to keep that at a minimum. A little kissing, and little groping. Maybe go down on each other. But you want to try to seal the deal quickly. If you do the one, two punch, you can be balls deep with little, to no resistance.

Also, it seems like your mother hasn't raised you til you got older.
How long after birth were you with your mother?
Did you go immediately into foster care?
The time spent during child birth and right after is when a mother has the strongest development between the bond of mother and child. Things like holding right after birth, breast feeding, etc increases the bond between mother and child. This is what normally causes a mother to end up not being attracted to her son.
If she was not part of any of this, her aversion to not wanting to fuck you could be much less, meaning your chances at being with her could be much stronger.
There is also the genetic attraction. Long story short(probably) look somewhat like your mother, but in male form.

Yeah, this post kind of turned into gibberish, but for the most part, they're my tips