If she is reversing letters and numbers it is quite likely she hasn't been taught to form them correctly in the first place.
Make sure she starts in the right place (usually at the top) and forms letters with the correct sequence of movements.
Curved letters c, a,d,g,o,q,s e are formed anti clockwise where curved numbers 2, 3, 8 are formed clockwise.
Once the correct formation is established she won't have to think about it.
I also teach my children letter formation jingles which they recite to ensure they form letters correctly in a smooth single motion
Curly caterpillar family
Anticlockwise movements
c round
o round, round and join
a round, up, down and flick
d round, up, up, down, down and flick
g round, up, down, down and round
q round, up, down, down and tick
s round and round the other way
f round, down, down and round ? across
e across and round
one armed robot family
down, up and over movements
r down, up and over a bit
n down, up, over, down and flick
m down, up, over and down, up, over, down and flick
h down, down, up a bit, over, down and flick
b down, down, up a bit, over and round
p down, down, up, up, over and round
k down, down, up a bit, over, round, out and flick
long ladder family
mainly down and round movements
l down, down and flick
i down and flick ? dot
t down and flick ? across
j down, down and round ? dot
u down, round, up, down and flick
y down, round, up, down, down and round
zig zag monster
diagonal movements
v down, up
w down, up, down, up
x down, stop ? down, stop
z across, down, across