Do I tell her and be the better person or not tell her?

My mum and her mum where friends from they were 21 years old. They were both pregnant at the same time with us, so we grew up together.

They also lived 2 houses down from us, so we would be out playing all the time, have sleepovers and we would never leave each others side.

We started primary school and again stayed best of friends until primary 5 (year 5) until we were around 9/10 years old. She found a new group of friends and completely changed, she never included me in this circle and every time I tired to hang out with her she would walk away. We completely drifted and I felt so lonely. I would be on my own alot in school but I eventually found another group of friends, however let’s just say we weren’t exactly the most popular kids, we got bullied alot and she stood by and watched it happen.

Anyways, fast forward to high school (secondary school) and I didn’t want to walk in on the first day on my own, therefore my mum had to ask her mum if she could meet me to walk along together, however she said she was going with the other girls and her mum practically had to beg her saying I had no friends etc.

She hardly spoke to me in school, always walked past me, I was so confused as to what her problem was but was never confrontational enough to ask. Even when we left school she hardly spoke to me, we never hung out anymore and tbh by this point I wasn’t bothered, I went to college and found lots of new friends.

She left last year to immigrate to Australia and invited me to her leaving night, which I went to. Fast forward to today, she came home for 2 weeks and never told me. She’s posting lots of pics out with her friends etc.

I found out I was pregnant and due to tell everyone soon, I don’t know why I feel guilty about not telling her before I post on social media because of how she treated me? But i just feel because our mums are still friends, she will wonder why my mum didn’t even tell her.

Would you guys tell her? Or am I too soft?😂