I made a sim family with two married adults, a young adult and teen. I wanted the young adult and teen to be sisters but had to make them mother and child. When I sent them to sleep in a bed together they keep refusing. The Sim's face is in a bubble with a "No" symbol threw the face and under the face is a bed I tried all kinds of cheats threw downloads and master controller.
unless I downloaded it wrong the cheat that lets me have any one sleep in a bed regardless isn't working. Maybe I never downloaded it or maybe its just not working.

I tried severing there family ties to strangers and they still refuse I can't set them as sisters for some reason.

I tried setting them as best friends, lovers and married and they still refuse to share beds.

I tried Members returner settings so sims can share beds and they still refuse to share a bed.
What else can I dry? and what master control menu changes how much they like or hate each other?

Two sims who do not like each other enough will not share a bed together no matter what. When one refuses and stomps their feet, they will probably have the thought bubble of the other sim appear, as if they are "in the way." If you want to improve their longterm relationship score with each other, that would NRaas > MC > (Sim) > Intermediate > Long Term Relationship by Value.

If you want to make them siblings, it's NRaas > MC > (Sim) > Advanced > Family > Add Sibling. The MC Cheats add-on module is required for this one.

If you want two sims who are not blood related but already do like each other enough to share a bed, and at least one is a teen or a child, you need the NRaas SleepFreedom mod, the bed will have to be replaced with a fresh copy after putting the mod in, and it only works on EA base game and EP/SP beds, not any custom ones or any from the EA Store. Strangely enough, without SleepFreedom the unrelated sims will still share a bed for other purposes such as napping or reading a book, but not for sleeping.

Thats a few things I didn't know. I never replaced the bed and Im not sure what bed Im using. They DO relax together now when not distracted by objects in the house, which they were not before. Apparently they had to apologize for something. I also don't know what number to enter for the value. and Im having a hard time changing there family tree since it considers them the wrong age to be siblings. That or Im in the wrong thing.

Given that there are almost 20 (real life) years between me and my youngest brother, as there are between my Mom and her youngest sibling, I would be really surprised to learn that two sims are the "wrong age" to be sisters. But if you can't do it that way, then use the same Family function to give them the same parents (Add Parent or Add Child). That should make them siblings.

For what relationship value, try anything over 60 for Good Friends and over 80 for Best Friends.