NB: This falls under the category of ‘mystic experience’ or ‘personal revelation’. In other words, her experiences aren’t – properly considered – theological expressions of the magisterium. That is, what she says may or may not be consistant with what the Church teaches; her assertions, then, are hers and hers alone. You are free to accept or reject them – there’s no requirement to hold to them as Church teaching that binds Catholics.
If you use these, Carlos, then you might consider framing up her statements as one example of what Catholics might think about purgatory; but you shouldn’t present them as authoritative Church teaching.
Edited to add:
From the link that Vouthon provided to Benedict’s talk, we find the following:
In other words, the mystical experiences of the saints aren’t theological assertions, but may be useful in development of theological theories…