In Britain, we call a pacifier a dummy. A diaper is a nappy. These are the standard terms. I don't know of any baby words for bottle or nappy. Where I come from, a dummy is referred to as 'dodo' when speaking to small children.

I think you're overthinking this a little. There's nothing wrong with speaking standard English with her. People don't use technical or very formal words with small children because they won't understand what they mean but the words you've mentioned are the standard names for the items in question; you don't have to simplify everything in order for her to understand. If your daughter doesn't completely understand then point out the object at the same time as saying the word and she will get the message. N.B Pacifier = 'dummy' in British English and 'diaper' = 'nappy.'

As a general rule, we don't use different words when talking to kids. American parents talk to their kids about pacifiers and diapers, while British parents would talk about dummies and nappies. OK, I'll admit that 'dummies and nappies' sound like babyish words to anyone who hasn't heard them before, but those are actually the proper British words for pacifiers and diapers. And bottles are just bottles.

In America diapers are diapers bottles are bottles and you can make up whatever word you like to talk about a pacifier.

I agree that you don't need to use different words. By the way, many families have or invent a handful of their own private family words for things! We always called pacifiers "binkies" when talking to the baby.