Don't buy anything till you're good and ready and happy with your choice. A lot can be tweaked, but not everything, so you really do want to start with a bike that fits well. Proper fit really matters. There's a plus to having a woman cyclist about your size helping you pick, I think. Ask her what OTHER brands she might recommend, to see if she's able to discuss bikes beyond Bianchis.
I have a Bianchi Eros Donna and absolutely love it. But that's not the point--point is, do more test riding, search on some threads here for fit discussions, and follow your best instincts too, not anyone else's pressure.
"My predominant feeling is one of gratitude. I have loved and been loved;I have been given much and I have given something in return...Above all, I have been a sentient being, a thinking animal, on this beautiful planet, and that in itself has been an enormous privilege and an adventure." O. Sacks