My G/F is coming from nepal in F1 on august and i am on my H1B can anyone write to me can she transfer her status to H4 dependent right after she come to US?? or how long it may take for her to get H4 Dependent processed. Does she have to be in F1 for long or a full semester??

No, there isn't any law that says F1 should be in that satus for any period of time before changing the status.
If you have any proof of marriage, your can apply for change of status to H4. But make sure she checks in with international office in university and enrolls in classes. It is important to maintain current status untill it is changed to any other form.

Thank You Prakash Ji,
Can you tell me if this process take a whole cycle of one year like Quora of H4 dependent or this is a quick process??

Sorry i mean is there any Quota for that??

If you already have H1B, as soon as you two get married, she can apply for status change.
Like Prakash Ji said, she needs to enroll in classes, go to school, maintain her F1 status until she gets approval notice on her H4 application.
Finally, good luck and congratulations !!

Your Tuppi.

Thank you Tuppi....

Can you tell the Processing period how long may it take?? otherwise i have to change my working place.........

It's hard to tell, usually status change takes about 90 days. At least, that was our experince.

Your Tuppi.