Well, it's hard to say for certain. Sometimes shows like 'El Presidente' take some inspiration from real-life but mix it up with fictional elements to make it more interesting. So, it could be a bit of both.
I really don't have much information about Dulce Singer. However, generally speaking, a singer's life story often involves elements like musical influences from family or friends, the struggle to find their unique style, dealing with competition in the music industry, and trying to connect with an audience. If Dulce Singer is a real singer, she probably has her own story full of these and other experiences that are yet to be discovered.