Damned if you do, damned if you don't in my experience of a serial nc parent. I broke one nc (for not telling him my brother and his wife had split up) with my dad upon becoming pregnant with ds2. Was more or less accused of being emotionally manipulative using the baby but we settled into an uneasy, walk on eggshells period of contact through the pregnancy.
My dad went NC again the day I gave birth. This was because he wasn't informed in a timely enough manner or the correct order of priority. Long back story involving perceived favouring on my part of my mum following their divorce. Mum lived in the same town as me, he lived 150 miles away for context, so yeah, I did see more of and spend more time with my mum than I did him.
I called him within 20 minutes of giving birth at 7.00 am on a Sunday morning from the delivery room. First I got told off for waking him but then I told him I had a good excuse, laughing, told him he had a new grandson. He then asked if my mum knew, I said yes because we'd called her at 4am to come stay with ds1 (then 5 yrs) while I went to hospital and again, just before I called him to let her know about the baby but mostly so I could speak to ds1 and tell him about his new brother. Deathly silence - for 12 years.
Me, I'd send a card on the safe arrival of your baby, OP. If she's the one who chose to go nc, she can't blame you for not letting her know you're pregnant. If she's anything like my dad she'll find something to complain about whatever you do.