一生桃花全换过

The direct translation means 'I have changed my lover(s) many times in my whole life, and every single period was as flourishing as the pink peach blossoms'. A metaphorical explanation would be: the person has encountered a lot of romantic opportunities and has switched between them all, suggesting that either she had multiple failed relationships throughout her life (maybe reflecting on regret or change in attitude towards relationships now), or else she simply likes changing boyfriends all the time indicating an open minded view and casual attitude towards love.