I have had problems with having sufficient upper body strength for long casts also, also fishing most of the season with a back injury and new fractures to 2 vertebrae has placed an importance of not straining or reinjuring things when making a long cast. Here are few things I have found to help overcome this issue:
1 I use longer rods and can get more distance with a 7ft or longer rod, I switched to using Setyr rods this year and the combination of lighter rods with more length has greatly improved casting distance. I also have less fatigue with fishing all day or multiple days in a row by using lighter weight rods like the Setyrs, they are very strong rods, but lighter and the handles are more friendly for a female with smaller hands, these rods are also more sensitive. Rods with less handle length below where the reel sits also help me cast further. In the past I have also taken rods into Southwestern Parts and Service and had them shorten the rod butts between an inch and 3 inches depending on the rod to make this part shorter and the rod lighter in weight.
2 I use mostly Shimano Curado Super Free reels, seem to get better distance with better reels, also do well with the Shimano Chronach ?sp that I use. If I had the money to invest in new reels right now my favorite choice would be using the Ardent reels with 11 ball bearings, excellent casting distance with those reels. (I am not sponsored by any reel companies,these are just suggestions from my experimentation.)
3 I will typically use lighter line than what alot of folks use so I can get better casting distance.
4 You can spray the rod guides with either Reel Magic or KVD's line conditioner and that will also improve casting distance, esp if you are using a light bait.
5 I have the brakes on the reel set as light as possible (usually only 2 on opposite sides of the curado super frees) With the type of line I usually use, I do have to have fresh line on and not be casting in the wind or with light baits for this to be effective.
6 If she is fishing plastics, have her put on a slightly heavier weight to get a little more distance.
7. If I am fishing with someone who has the boat farther away from the bank and i can't make the throw to the bank, I will start throwing a Carolina rig, even in shallow water, sometimes it is more effective anyways, esp in grass.
Hope these suggestions are helpful, and I think just spending time on the water casting is what makes the most difference.
