Julyn,
Yep, info is hard to come by. However, the Hong Kong Disneyland internet site does provide basic info on the attractions, restaurants and the two hotels, the Victorian style Hong Kong Disneyland hotel, and the Hollywood Hotel. When we were there in November, I asked around at the downtown bookstores for a guide, but apparently nothing (!) was available. I thought that I could pick up something at Hong Kong Disneyland itself, but even there, no go - no book of souvenier photos, no basic guidebook (other than the usual - and in itself quite informative - free hand-out map) and not even any postcards with photos!
Popcorn and hot dogs are available, but one of the nice things we found about Hong Kong Disneyland is that all of the restaurants served Chinese food. (Yes, Western as well as non-Chinese but Asian options were available.) Moreover, each of the restaurants seemed to specialize in a different type of Chinese cuisine, so you could - if you liked - take a gastronomic tour of China. I'm sure you'll find something your MIL likes!
The price / quality was reasonable, about on par with the better restaurants in Hong Kong. (Slightly more expensive than in the US, but not that much.) We enjoy Chinese food, and couldn't fault the quality. Not haute cuisine, but definitely not junk food quality.
We tried quite a number of the restaurants, but couldn't tell you off hand if any in the park offer Character meals. However, this is available at the two hotels - at breakfast, Mickey, Minnie, Goofy and Pluto spent quite a bit of time with us. (And the breakfast was a wonderful blow-out, with a huge assortment of Western, Chinese, Japanese and Asian regional food, almost all of them delicacies.) In all, very much like a Character meal in Orlando or in Anaheim.
As for hotels, we stayed at the Hong Kong Disneyland hotel, but we also visited the Hollywood hotel. Both are within walking distance of the entrance to Disneyland; the Hollywood hotel is about five minute's walk farther away. The shuttles go frequently, so you don't have to hoof it if you don't want to.
We loved the Hong Kong Disneyland hotel. The rooms were very comfortable and the staff attentive. The lay-out is very beautiful, and the Victorian theme is done very well. In early November, there were very few visitors, so we were really pampered. My only complaint: the spa that is connected with the hotel had fairly steep prices - certainly more expensive than what we would be prepared to pay. However, the company that runs the spa is well known, and I'm sure the quality is top level. If you really want to be nice to your MIL, you might think of splurging on a two-hour treatment.
The Hollywood hotel is also themed very attractively, and again, the staff was very attentive. The rooms seemed somewhat smaller than at the Hong Kong Disneyland hotel, but the ones we peeked in still looked quite comfortable. Since there were only the two of us, we didn't ask about larger rooms at the Hollywood, but I know that these are available at the Hong Kong Disneyland hotel.
As for the park, it was easy even for non-Chinese-speakers to get around. All the signs were also in English. On the rides that come with a commentary (such as the jungle safari) there were separate lines for Mandarin / Cantonese-speaking and English-speaking guests. All of the staff that we came across spoke very good English, even if they at times stumbled over the stock tourist industry phrases that are not commonly used in China (although they are heard in Hong Kong), such as "How may I help you, ma'am / sir?", and "I am sorry to keep you waiting, ma'am / sir."
All in all, a great experience - and we also loved visiting Hong Kong for a few days. I'm sure you, your kids and your MIL will have a great time!