I don't believe you can do therapy much more efficiently, and I fear talking faster to squeeze everything in might not give you the time you need to process the significant things about which your talking.

Two suggestions:

The easier one is to write a letter and have her read it at the start of each session. Have it cover everything you want to talk about so she can go from beginning to end. This can help you open up a bit more emotionally before the start of the session so you're ready for processing and give her something more concrete and faster to process than the spoken word. I do that sometimes, it's basically a way of extending the therapy because I start before she does- I start when I write.

The second suggestion, which I recommend highly if at all possible is to see her twice per week, or to get a double 90 minute session instead of 50.

In lieu of those, or even along with those, try to remind yourself that therapy doesn't have to happen in a rush or on a timeline, you and she can hopefully work together as long as it takes to talk everything out, there is time.

I've struggled with this issue too, and the above things have helped, hope they help you too.