My sister is a virgin and her fiance is also a virgin whom she met through arranged marriage proposal in India..

She gave him a handjob yesterday

She also touched his semen once he fully ejaculated..and she had a Small Healing Skin Scrape on Upper Side of Thumb while doing the handjob(she had pulked the skin of the side of her thumb and thats how the skin got peeled)..the skin scrape had happened 2  or 3 days before the handjob was given..

It was in Healing process.. but Her doubt is that will she get any STI like Herpes or anything else if the semen had passed through the skin scrape ?..any chance of this?

You seem to have a basic misunderstanding about STIs. They are not simply infections that happen to involve the genital area. The bacteria and viruses that cause them evolved to require sex itself for transmission. That almost always means that if there is not direct genital contact -- usually with a penis entering the partner's vagina, rectum, or mouth -- there is no risk for STI. In other words, the kids of exposure you describe, both in your other question and here, do not count as sex for purposes of STI transmission. There is never any STI risk from hand-genital contact, including contact of semen with skin anywhere on the body, including skin with nicks or cuts, and including mouth contact with small amounts of sexual fluids.

On top of all this, of course there is no STI risk if one partner is not already infected, and it sounds unlikely your friend's fiance has an STI, don't you think? But even if he did, your friend could not have caught it.

Therefore your friend's "doubt" she will get an STI is correct.  More than doubt, there is simply no chance of it!  I hope your concerns and questions about this did not worry her unnecessarily. Let me know if anything still isn't clear.

HHH, MD