I notice her changing gears there was a clanking noise and it looked when i was side onto her that the gears where slipping and she would put the gear back into a higher one, i get the feeling she isnt 100% happy with the bike
Gear woes are a sure way to make someone hate their bike.
Thankfully it doesn't necessarily mean anything is bust, and is often pretty easy to rectify.
I seem to recall from your first post that the bikes are quite old. I presume they are not so old as to pre date indexed gears? Ie do you have levers and you have to sort of feel for the gears as you change, or do they just click into position (either by clicky levers, triggers or twist grip)?
Assuming they are indexed, as I believe has been the norm for at least 20 years now but I could be wrong, then a simple cable adjustment might be all that is needed
First thing I'd do is make sure nothing is sticking. A good clean and lube should sort that. A blast of WD40 into the gear components and chain would be my starting point. WD40 is frowned upon by some as dirt sticks to it, but I find on older parts its fine. Just wipe off the excess and let it dry off before next ride.
With everything moving nicely, next I'd want to see if all gears go in nicely when not under load. Bang it in first then lift the back wheel off the ground, select second then turn the pedals with one hand while holding the bike up with the other. Repeat one gear at a time all the way to the top, then back down again. In an ideal world, the gear changes will be smooth, almost silent, and happen within about half a revolution of the pedals.
If you find it hesitates to change, or if it makes a lot of ticking / rattling as you pedal, chances are the cable is not tensioned right. If the bike is old and hasn't been tuned for a long time, most likely the cable is slack because they stretch over time. There is often a barrel adjuster either at the shifter end on the handlebars or on the derailure itself. With a middle ish gear selected (eg 3rd or 4th), and the bike upside down, you could adjust the tension on the cable until it runs nicely.
If bottom or top gear specifically are a problem, ie if all gears go in nicely except bottom or top, then most likely the high and low limit screws need minor adjustment.
Finally if all is great in the lower gears but it gets more sluggish to change into the upper gears, then there is another screw for that, but it's generally best not to touch that unless you're prepared to fiddle quite a bit.
Cable tension would be the first thing I'd check though.