Their parents toiled their whole lives to raise them.
Tips
usage
劳苦 combines 劳 (labour) and 苦 (bitter/suffering) - emphasizes both the work AND the hardship. Compare 辛苦 which is more 'tiring/hardworking' without as much weight on suffering. 劳苦大众 ('the toiling masses') is a common revolutionary-era phrase.
