Hi hun,
Are you talking about W2S? There are a few diff ways to do this, but you can try going in and stirring (barely) your LO about 10 mins before she wakes. This will reset her sleep cycle, and hopefully she will sleep longer. Sometimes it can take a while to get the timing right and I would then stay in the room past the 45 min mark and if your LO starts to wake try HTTJ, shh/patting or pressure to extend as a back up
There was a post on how to do this and your options, but I am not sure where so will see if I can find it
I think 3 days is usually what it takes to break a habit...I had to do it for weeks
but you can always do it for say 5 days then give it a rest to see what happens.
HTTJ is where you use the pressure to get your LO through the jolts - which is what you are doing. Do you swaddle your LO, this helps sometimes.