hi cheekystar,
your mum will love the balloon flight, we went up in one for my mums 50th and it was fantastic, really lovely it was. we landed in a corn field just as the sun was setting and we were all given a glass of champagne.
i think scarletts idea of a small piece of jewellery is a good idea, maybe a little pretty pendant or something..?
theres some lovely little gem stone necklaces around, maybe you could choose one that is her birth stone?
hey, just a thought, i treated myself to a lovely little heart pendant a while ago, from argos, it was only �20, but its really pretty and ive had lots of compliments about it as its such a lovely colour, and as it happens its the may birth stone, emerald, the same as your mums.
have a look if you get chance, they do the full jan to dec range birth stones, but the pics in the catalogue dont do them justice, so try and nip in the shop if you can as theyre much better in real.
i hope your mum has a lovely birthday, it sounds like it will be one she will remember!
let us know what you buy her :o)