It happens with folks from many countries either across to other countries or just within one country.
 
My father deliberately cut himself off from his mother and for very good reasons and a few years later a brother found my dad to tell him their youngest brother had passed away, in the same phone call dad discovered that 6 of his 9 siblings had progressively cut themselves off from the mother and discovered that his mother had passed away and not one family member attended her funeral. 
 
It happens.
 
I'm also aware of a case of a refugee family from Vietnam moved to Australia under a refugee assistance program, mother, father and 4 kids (kids were all born quickly one after the other so their ages quite close).
 
They had been in Sydney for several years, kids all in high school, good kids, doing well, suddenly mother and father disappeared and couldn't be found by the police, welfare services took care of the kids.
 
Quite a few years later (the kids now around 20 to 24 years old, all at uni or finished uni and in good jobs) the parents were found in VN, they had moved back to VN without telling their kids.
 
In this case the kids all decided they didn't want to return to VN and indicated to the parents that if they came back to Australia the kids would not contact them or support them. 
 
It happens.

Oh wow I almost missed the last half of your post about the kids in Australia I just noticed that I almost forgot to read that part. I just read your second story and that’s a terrible thing to abandon your children. I would never even abandon my pets. When we lived in Japan and now here in Thailand we brought our pets with us. It’s difficult and expensive but it was worth it because they are still with us.

Thai women who are on a US green card should get naturalized US citizenship if they ever plan to return and live in Thailand. They can carry two passports without problems. The biggest reason is with US citizenship they can receive US social security in Thailand. Without it they can not. 

 

Actually yes they can. My wife is a United States Permanent Resident (green card holder) and just began receiving her Social Security from the United States. As long as you worked in the United States and paid taxes you are eligible for Social Security regardless of citizenship.

 

My wife does have a lot of Thai friends in the states who are United States citizens and some of them do still travel here on their Thai passports they just keep their Thai passports and still renew them and no one is the wiser. If they are only going to Thailand for a short time they’ll use their US passport. I don’t know how they get away with it but some of them have done it somehow. But anyway no you don’t have to be a US citizen to receive US Social Security my wife’s getting hers now from the states and she’s a United States Permanent Resident. You don’t have to be a United States Citizen to draw Social Security from the United States

Its true if you live in the US, but it changes if you move to Thailand.  Also, she'll lose her green card if she returns to live in Thailand. The rule isn't exact but generally 6 months is it. If you apply beforehand you can do a year. If you repeatedly do 6 month in and out could be a problem. 

Both Thailand and US don't have a problem with dual citizenship anymore.

Its true if you live in the US, but it changes if you move to Thailand.  Also, she'll lose her green card if she returns to live in Thailand. The rule isn't exact but generally 6 months is it. If you apply beforehand you can do a year. If you repeatedly do 6 month in and out could be a problem. 

Both Thailand and US don't have a problem with dual citizenship anymore.

 

You’re right about the green card but you’re wrong about Social Security I know because my wife just started receiving her Social Security and we’ve been living here in Thailand now for 5 years. Ask the Manila Social Security Office if you don’t believe me (if they’ll respond to you lol) but it’s a fact I’ve seen it for myself. She is most definitely eligible for Social Security and she is actually receiving it she just started recently.

 

When I was in the military she used to travel overseas with me all the time and we lived in Tokyo Japan for years and she’s never had a problem getting back into the United States before on her green card or rather Permanent Resident Card same thing I know. What you said maybe partially right. But I know for a fact about the Social Security because we’ve been living here 5 years and she’s getting it, this month was her first Social Security payment. And she is a United States Permanent Resident

 

Or I might be misunderstanding what you mean

Social Security and Non-Resident Aliens is convoluted, but do-able.  https://www.fool.com/retirement/general/2015/03/08/social-security-5-surprising-facts-about-noncitize.aspx

Social Security and Non-Resident Aliens is convoluted, but do-able.  https://www.fool.com/retirement/general/2015/03/08/social-security-5-surprising-facts-about-noncitize.aspx

I mean it was difficult dealing with the Social Security Office in Manila but I successfully helped my wife get it done it was just a bit of a hassle but extremely doable.

Anyway Social Security is getting off the subject here this topic is about helping this lady find her long lost daughter in the states