Welcome to the forum brother!
You will get all the originals back when your wife gets her Visa, so you are looking at 16 months if your case is straight forward. Make copies of all the originals you are sending and if possible get it attested. Also, it would be a good idea to scan the originals and keep an electronic copy of it just incase if she needs it for something. Everyone from Pakistan is supposed to send the original birth certificate, educational certificates, Nikkah nama/ Marriage certificate etc, so there is no way to avoid it.