Blouse is a great word, I don't think any of my kids know what that is....I had better teach them that one!
I have read many comments similar to yours on this forum. The general advise is "just keep going!" many parents have commented that 18 months is a turnaround point where their babies just suddenly started to show them what they knew. Personally I believe in Imput Imput Imput! Just keep up the quality Imput! Don't have any expectations for any results at all. Your job is to teach, not test. testing is for schools
teaching is for mums!
Since she obviously likes the flash cards with pictures, keep using them. Always show the word even if you think she isnt interested. Look at it this way you have a toddler who knows what a blouse is...I have 3 school age kids who DON'T!
She is learning lots, even if she isn't showing you she can read yet.
Do you have little reader? ( if not do download the free trial version, it's great!) It has loads of words with the pictures of all of them. It also has some phonics training. You daughter might be internally figuring out the rules of phonics, teaching her phonics may just speed up her reading.
Have faith, keep going!