Will her family - given she's a street vendor - "get" how he was conceived do you think
No reason why not. Surrogacy wasn't a big thing when I was there. But by the looks of it's significant expansion as a business ... in areas of poverty, it won't be unknown. Not least cos I'd expect a decent amount of "grassroots" recruiting of wombs going on and they be keen to spread the word that nobody is asked to have sex with a stranger or "sell" a biological child in order to participate.
But... never underestimate human ability to pick up any convienent stone and use in a row/when drink has been taken. Even if they understand and generally don't have a massive moral issue with surrogacy to allievate economic disadvantage.
I think the husband is the one more likely to cop the worst of that. Snidey comment from workmates, neighbours and drinking buddies that allude to him being cuckold are not beyond the realms of possibility. Which could put pressure on the marriage. Worst case scenario is the marriage crumbles under various pressures, he leaves and takes the pre existing children with him. It's not an impossibility that if it all goes bent the cost of them keeping this child means her losing her other kids.
I think the best bet for them being rather more impervious to judgement and snideness is for continued media/international grassroots interest in the child over the years. Not a blinding spotlight and . Especially something that underlines the high moral points of what they have done. Something that makes people feel good, like "The Thai savoirs of a child abandoned by falang". Big them up like that long term, thus save their face and make them less easy a target. If the people donating today set up a website, in english and thai, intended to maintain longterm interest and donations, that was full of praise for the Thai parents, that could keep the family visible in a postive way long term.
And it might help for the funds raised to be managed externally and ekked out over the child's life so the parents aren't left vulnerable to hoards of firends/family coming out of the woodwork with a sudden need of a "loan" or "investment opportunities". As long as they have an improved, steady and reliable income they could gain significant immuinty from any shitty behavoir towards them. Whereas it is much harder to take on shitty comments about your masculinity/surrogacy AND try to take care of a child with significant needs AND be scrabbling around for money you don't have.
Wouldn't be a bad idea to appeal to a swishy BKK's hospital's desire for excellent international PR by getting them to offer to cover the child's health needs pro bono for life either. To avoid urgent medical needs making a massive hole in the funds raised right from the start. What they and the baby really need is a lifelong stipend.
That together might help protect them from drifting into obscurity and an economic reality that makes them so much vulnerable on many levels, including social pressures and/or derision.