What happens if it runs out whilst she's there?
I can only recount my experience of extending a visa in Vietnam, not a pleasant experience, considering I was staying about an eight hour car journey away from Saigon. (only Vietnamese passport holders are allowed to drive, so it meant hiring a minibus, with air con! A hundred dollars round trip.)
I had to get a local policeman to sign a paper to say I was residing in the locality, along with a reason.
I had to take that form, with the exisitng visa, i.e. passport, to Saigon, pay a fee, (more or less for another visa), leave the passport there for a week and return a week later for it. The visa offices are not pleasant places to hang around in.
It cost about two hundred dollars for the car hire and about a hundred dollars for two overnight stays in Saigon.
But Cambodia is openly more corrupt and a few dollars in the passport might go a long way.
Having said that, getting a UK visa for a friend's Mum was horrendous. She had to fly to Hanoi to the UK embassy and answer questions that she had no understanding of, e.g. what did I do for work. And she would have to pay for the interpreter. She was suffering badly from diabetes and could hardly walk, never mind travel that far just for the interview. She did eventually fly to Hanoi, but becasue she was late for the interview it was cancelled and she would have to re-apply. That was a days car journey to Saigon then the flight to Hanoi and back, then the car journey again, accompanied by her daughter.
The visa cost over a hundred quid.
It had taken over a year and multiple visits to various government offices just to get a passport for her. All the time her health was deteriorating.
Eventually, the interview was conducted by phone, on my mobile at her house and because she couldn't speak english and the interviewer couldn't speak Vietnamese, my friend answered all the questions.
It would have been a joke if it hadn't cost many months of wasted time, wasted money and a wasted journey to Hanoi.
We were allowed, eventually, to collect the visa from the Saigon office, but the passport had to go to Hanoi for the visa.
Oh and by the way - you really need to learn to differentiate between immigration and race issues.
You should be on the stage............sweeping it.
.
And you need to differentiate between migration and immigration.