Hi, here are some rules:

• you have to include one language(core/elective/functional)
• you have to include the subject you wish to seek admission in, otherwise you face a disadvantage of 2.5% while calculating best of four
• the other two academic/elective subjects should be mentioned in the "List A" provided by DU.

Physical education is mentioned on this list but it will only be treated as academic/elective only for honours in physical education. So the answer to your question is that yes you can include it in best of four but if you aren't opting for honours in the same then you 2.5% marks will be deducted from you best of four.

the answer to your other question is that yes there are 1% to 3% relaxation of marks for girl candidates but only in a few colleges or courses. Not all colleges and courses in DU provide this relaxatin of marks.

good luck