Advice plzz

So, there’s this friend of mine, Liz. We were best friends since elementary school and would go to each other’s house all the time. Long story short I found out that our mothers are cheating. One night my mom was laying in bed with me and she fell asleep. I saw that she recieved a message and I opened it to find pictures of one of my dads cousins posing in sexual manners and saying that he wanted Liz’s mothers boobs. I immediately told my dad crying in disbelief. My mom said that it was my best friends mother that would text him using her phone because she didn’t want to get caught. My mother also told us that Liz’s mom was cheating on her husband with his brother in law. It’s been about 3 years, and within those three years we’ve texted a handful of times. I never got to say a proper goodbye to her since my parents told me to block her and her family on all socials, even though she did nothing wrong. She doesn’t know what happened, I’ve never talked about it with anybody. Only my dad, brother and mother. I didn’t tell their family because they have really young children, one was only a couple years old, we didn’t want to break the family. I really want to text her, I miss her so much. I just don’t know if it’s fair to her. I feel terrible for not telling her anything. But I also miss her a lot. When all of this went down, it was my freshman year of high school, I was so happy. Happiest I had been in a while. She would be on her phone a lot, I’ll admit, but still we had fun. My mom said oh well she wasn’t a good friend anyways, she was always on her phone. That’s a terrible excuse. I really thought my parents were finally going to get a divorce but they didn’t. They argue a lot and I thought this would be the breaking point but it wasn’t. Now my family and I are okay I guess. But I want to talk to her. What should I do? I forgot to mention, I recently graduated. I’m 18 and live with my parents. If I do talk to her, what should I say? When is it the right time?