Invest 2000 Euros In Cryptocurrencies [Urgent]

Hi, this is very serious, I and my brother have convinced my mother to invest 2000€ in cryptocurrencies, we told her Bitcoin because she was going to invest it in a bank with "Livret A" we call it like that in France and it gives like steady 1% return a YEAR. So Can anyone tell me in which cryptocurrency should she invest that 2000€, Which platform is best for low fees? Thank you guys, your advice is appreciated …

Also, she will invest this money today.