Where are the 2 computers in relation to each other? Same building, on the same local network? Across the state; your RDP session uses The Internet to make the connection? 10ft distance , 50' via cat 5 & office network switch.
What are the screen resolutions of the 2 computers? Recommended defaults. Do you have more than 1 monitor at one or both systems? One monitor hers, two @ mine.
Do you have an 'active' screen saver or backdrop screen on your main computer? Lots of sounds? Usually, RDP does not bring the sound and background screens through to the computer running the RDP session-- that's one less thing to process? When I log on, all that stuff on hers is off. I could have several spreadsheets, PLC & HMI programing along with email and MHs formum all running on mine.
Do you enlarge the window you're working in to take the full screen? It is full screen on the 2nd monitor If the computer doesn't have to keep refreshing the other windows, it can dedicate more effort to what you're working on.
Is everyone else at home when you notice the speed increase? Have you noticed the speed is not faster at all times of the day, say, for example, mid-morning when everyone's pounding away at their machines to get work done? N/A