She never will think that cheap like GW and do such a dhrogam to her poor and loving sister. Puvi might scold his bro, but won't do such a thing for the sake of money. Why would they want more money if they have enough? I can't even imagine that, i am really loving Thulasi-Sudha relationship and she is the only strong woman in this serial to support Thulasi.Psycho's dialogue might just hint that the spy has to be someone well known to GW and someone close to TA so that she would be shocked if that person does dhrogam to her son. Moreover Puvi and Sudha were not really close to TA and neither to GW.