Help with Grace quest

Hi guys so I've been working my way through some of my quests and have done a few charity events for Grace Worthington. After the last one, she met me outside my Bel Air house and is offering me a baby elephant for 100k stars - is this a one time offer? If I don't accept will I lose the elephant forever, or will it be more expensive at a later date for me to purchase? And advice appreciated!