I can only realistically see a Racially Aggravated Section 5 Public Order Act (disorderly behaviour) charge succeeding arising from this. The more serious offence (Section 4A) needs to be supported with “Intent” to cause harassment alarm or distress. Given that the young lady is almost certainly under the influence of something or other it is likely that the charge will be the less serious one.
Section 5 is the part of the Act on which the delightful Denzel Harvey found himself on the receiving end for a prolonged stint of foul mouthed abuse aimed at police officers:
http://www.theanswerb.../Question1078364.html
You will see that his Honour Judge Bean suggested that such foul behaviour was so commonplace now that hardened police officers should not be troubled by it and he duly quashed Mr Harvey’s conviction.
It will be interesting to see if a similar view is taken about the behaviour exhibited by this shining example of an English Rose. It is probably true that black people are frequently on the receiving end of such abuse. So it is possible that the black people who found themselves unfortunate enough to be on the tram that day may be told that, since such abuse is so common these days they should not take any offence.
If convicted of Racially Aggravated Section 5 the maximum penalty is a fine of £2,500. No other penalty is available. Magistrates’ sentencing guidelines (for a first time offender pleading not guilty) suggest a “starting point” of a week’s net income.