If you can, I suggest you visit after 8 July. After this date (until 1 September) the two parks at the
Disneyland Resort Paris (as it is now rather clumsily called) have their extended summer opening hours. These are 9am to 11pm for the Disneyland Park and 9am to 9pm for the Walt Disney Studios, but I would say there is very little that would appeal to your daughter in the Studios. Although you might not want to stay up late everyday with your daughter, the extra opening hours do give you a bit more flexibility in terms of how when you visit the parks, and when you return to your hotel for a break.
I agree that the Cheyenne would be a fun place for you to stay. Be aware that it doesn't have a swimming pool - if this is important for you the Sequoia Lodge (my favourite hotel at DLP) is the cheapest hotel with a pool.
My best tip for visiting DLP is to make sure that you get to the park as early as possible - around 8.45am if you can. Like all Disney parks the queues for the rides and attractions can get very long in summertime. Shortest queues can be found in the first couple of hours of the day, which is why it is important to be there early. We normally dash around like mad things until about 11.30am riding as many attractions as we can, then take it easy for the rest of the day with an early lunch, seeing a couple of shows at the park and generally taking in all the wonderful atmosphere. DLP has added FastPass (please ask if you don't know about this) to some of the main attractions at both parks - most importantly for you to the Peter Pan attraction, which is very sweet but develops the most terrible queues from the beginning of the day.
There are several DLP regulars on this board, so please feel free to ask as many questions as you can think of. You could also try visiting
http://www.dlp-guidebook.de/index_e.htm which is a very good unofficial website about DLP.
Regards
Rob