How would one address oneself when speaking to royalty?

Question

Apart from avoiding using personal pronouns, when speaking to royalty, would one just use watashi, like in the following example:

Time: 05:32 - 05:50

http://www.dailymotion.com/video/x15jzz2_my-little-pony-tomodachi-wa-mahou-s2e01-japanese-sub_shortfilms

「お天気のことですか。生き物たちも皆おかしくなっちゃってるし、私の魔法も効かないし、これって。。。」 (edited with help from KyloRen)

Or would one use a different pronoun in real life?

Answer 1

First things first, it was actually this,

「私の魔法も効かないし、これって。。。」not 「これで。。。」

You certainly could use 私{わたし}, but you certainly could use 私{わたくし}.