A better solution may be to mix it with juice. Grape or Pomegranet juice works well. Make sure it is 100% juice with no sugar or fillers added. She can put a little bit of the straight oleander under the tongue where there are no taste buds and the absorpion is fast. The rest mix with the juice. Hold the oleander for a few seconds and then swallow. Then chase it down with the juice. Good luck and let us know how you do.
Luella
You have already gotten a couple of very good suggestions, and what Luella described is how I have always taken "oleander soup". It does taste yucky otherwise!
I think that gel caps is a good idea too and I would think that freezing poses no problems, as the makers of the patented medicine form of oleander extract (Anvirzel) freeze dry it and then the patient reconstitutes it with pharmaceutical grade distilled water.
All the best,
Tony