There is a lot of paranoia that's risen out of what.. 1-2 ladies that have been determined to be a scam in the past few weeks? Maybe 3 women? The odds of it being a scam are extremely slim. Most of the ladies have professional pictures taken for their profile, either initiated by themselves, or suggested and taken by the agency. They like to present their best pictures because they want to be desirable - who doesn't? I know that if I had professional pictures, I'd be sending those babies out :p You can simply ask her to take a picture of herself how she looks at work or on the weekend, or as it was suggested with flowers that you send, etc. I've told the ladies I speak to when I ask for these pictures that I would like to imagine what she looks like on an average day when I think of her, something like that *shrug*
Also, in terms of repeating, I am having that issue with one lady - mostly this is an issue with translation. When translating english to chinese and vice versa, there are certain things - slang, vernacular, phrasing - that don't translate directly. This means that the translator then needs to make a "best effort" at making the lady understand the basic meaning of what you are saying. Sometimes your basic meaning is skewed, lost partially, or lost altogether. I really wouldn't sweat it too much, but if it helps, maybe you can try to break down your writing into simpler sentences (I'm not sure if that is what's needed, just a thought) or write in a way that leaves little room for error or misunderstanding by the translator.
As mentioned, you may also wish to write every 1-2 days instead. Writing every day generally means that there is a lot of information being written about, therefore, a lot of things on a daily basis to remember. Your lady may also be getting confused between the letters - almost like forgetting what you had for dinner the night before
I like to have my most recent letter in front of me when I write my replies so I know what was spoken about, but this may not be feasible or something that your lady is doing, which could also explain the memory gaps.
Best of luck to ya!