O.K feeling the pressure!!
Apparently:
The Hundred=strengthens the Abs AND muscles in arm and shoulders.
Spine-twist [arms stretched out, twisting around at waist, hand to opp' ankles]=tone arms and conditions Abs and quads.

Other exercises in "the book" [that i'm about to return to library!!] use light weights, where you stand, heels together but toes facing outwards [pilates stance!] stand tall. draw in the powerhouse [ you knew i'd say that!]
THE HUG
1.Hold arms out to the sides of the body, with elbows lifted.[imagine you're hugging a large beach ball]
2. Inhale and squeeze the arms together with resistance, feeling as though you were pulling springs towards the body, bringing the hands to almost touch.
3. As you exhale, open the arms with resistance as though you were pushing heavy weights away from the body.
Perform the Hug 3 x, inhaling as the arms come together,and then repeat the Hug, reversing the breath by exhaling as the arms come together.
Perform the Hug a total of 6 times.

ARM CIRCLES

1.Stand tall in the tripod pilates stance, with weights in hand, arms down by sides.
Holding the torso strong, circle the hands away from the body in small movements, working your way up into a V position above the chest.
2. The circles are small, concise and strong and require that the body be held perfectly still. Circle 5 times to the up position and then 5 down. Inhale in asmooth, continuous fashion as the arms circle up and exhale as the hands circle down.
Do 3 sets.

Thats that then!! You can always use light weights [optional] and do that exercise that you're probably already familiar with..like the arm circles,..where you hold your arms straight out to the side of your body and rotate in small circles forward for a short period, then reverse direction..just small movements is all it takes to build up a burn in the arms..and push ups kill my arms, either the 'ladies' ones on your knees front ways OR in a squat with your hands on a step behind you, fingers facing to the front, lowering yourself down and up, bending at the elbows and letting your arms do all the work!!
{ hard to lift the cuppa to my lips after those!]

DON"T say i didn't try to help!! Now its up to you guys for more ideas!!