Pinky placement on bow

I'm a beginning violin student and am having a lot of problems with keeping my pink in the proper position. After two weeks of exercises, I still can only keep it where it's supposed to be for several seconds. My instructor told me to think of my finger placements as whole step, half step, whole step, so that there is a whole step between my pointer finger and middle, half step between middle and index, and whole step between index and pinky. I have short fingers, so it feels like it's a stretch to keep my pink that far, much less keep it covered and on the tip. Almost immediately my pinky begins to slide so that it's much closer to my index finger and resting on the pad. It then becomes arched and uncomfortable really quickly as there's a lot of strain on the joint. I'm getting really discouraged and am wondering if this is something I really just need to work on, or if I should try adjusting my fingers? I'm wondering if my pinky is too short to keep it where my instructor wants it?

Holding a bow is not such great philosophy. When you take the bow, your fingers will be automatically placed in the way you describe. Your problem is same as mine. Just try to place the violin little in front of you, or try to straight your thumb. P.S: Sorry about my English, I know it's awful.

Your English is fine. I see no mistakes.

Holding a bow is about your natural balance. A bow should be a seamless extension of the hand. Don't worry so much about pinky placement unless it causes a problem. It doesn't need to be perched directly on the bow just somewhere near where those annoying example books say...

spend time holding your bow, not playing. for example, see how long you can hold your bow properly while watching your favorite tv show, etc. Pinky placement is very important. this is because the whole weight of the bow is controlled by your pinky, the other fingers are mere passengers. you sholud be able to make you violin 'wave' vertically (up and down) using only pinky power. keep working on it!

Try not to use to much pressure on the pinky. It is the thumb and pointer finger that do all the work when bowing. Try playing eighth notes on any string only using your pointer finger and thumb. Then put the pinky and the rest of the fingers down and concentrate on not putting too much pressure on the pinky.