I whanau a Rösler i Khánh Hung, Ba Xuyên Province, i Vietnam ki te Tonga (i tenei ra ko Sóc Trăng Province, Vietnam) i te 24 o Hui-tanguru 1973. Kaore he korero mo nga maatua whanau Vietnamese a Rösler. I whakamanahia ia mai i te whare pani Katorika Roma tata ki Saigon e tetahi tokorua Tiamana e rua ana tamariki koiora, a i kawea mai ki Düsseldorf, Tiamana ki te Hauauru, i runga i te rererangi o te whakahaere atawhai tamariki Terre des Hommes i te iwa o nga marama. I whakatipuhia ia e tana papa whakatipu, he hoia hoia, i muri i te wehenga o te tokorua i te wha o ona tau. I tipu ake a Rösler i Hamburg, Bückeburg me Hanover, i reira ia i puta i te kura i te tau 1992. I muri i te whakangungu mo te whawhai i te Bundeswehr (te Federal Defence Force, Vietnam) i te tau 2003, i whakaaetia a Rösler kia ako i te rongoa i te Whare Wananga Hauora o Tiamana i te taha o Saigon e rua nga tamariki
te hohipera o te Bundeswehr i Hamburg