"My daughter is working as a lawyer over in England."
Translation:Tá m'iníon ag obair mar dhlíodóir thall i Sasana.
Because anall indicates movement towards the speaker of the sentence.
Tagann mo mhac anall ó Shasana.
My son comes over from England.
When there is no movement either towards or away from the speaker then thall is used. Thall indicates position. The daughter in this sentence is situated in England. No movement is implied.