aight based on limited info provided i see two plays here
you can either groom her for being in the background longterm
blackking covered this scenario very well
or...
you put a future expiration date on the situation
meanwhile try to extract as much value from her as you can

this was/is my preferred method
basically "wow" her with attentive companionship/sex for 5-10 hours a week

then assess how she can help you
if you do it my way??
don't take her cash or let her do anything sexually that she already doesn't do
that will cause big problems later
instead, focus on things like..
- mental assets
- her free time
- connections- who she knows??
- memberships/discounts- maybe you can get cheap gas using her sam's club card??
- borrowing her possessions (returning them in good working order)
a woman's mental assets are always a goldmine

evaluate what she does well- and replicate it or adapt it for yourself
maybe she can cook or is a good nutritionist??
get her to teach you how to make simple, healthy meals for one
that is "something" you can use for the rest of your life
or maybe she knows yoga??
get her to teach you the best stretches for a dude
or how to fix your bad ankle or wahtever
maybe she is good at bargain hunting and has an eye for fashion??
let her create a new wardrobe for you
reimburse her for the cost, but not for her shopping time...see??
guys aren't usually comfortable asking for help or to be shown something
but apart from my technical/financial knowledge
80% of what i know i picked up from women
i acquired many of my hobbies/interests as well
this versatility you gain is part of what enhances your worth as a prospective husband

it all comes from the building blocks of past relationships