You can create citations directly from Zotero now. Right click on the Zotero record and select 'Create bibliography from item'. This will open a pop-up window and you can select the bibliography style and outputs. Output mode should be 'bibliography' and output method 'copy to clipboard'. Click ok. Then paste into your Wikitree source section or as an inline citation.
I usually use Zotero for books and articles but have had a little look at how this behaves with an Ancestry citation. Saving to Zotero from an Ancestry record creates a Zotero record of a 'web page' item type. This can be used as is however the url is very long. In the url field of the record in Zotero add square brackets at the beginning and end with a space at the end of the url and the preferred display text before the closing bracket the citation. It will copy perfectly to Wikitree with the display text becoming the hyperlink to the record. You only need to do this once in Zotero. It will look like this:
“England & Wales, National Probate Calendar (Index of Wills and Administrations), 1858-1966, 1973-1995 - Ancestry.Com.Au.” Accessed October 20, 2017. Ancestry link.
If you would like to include the original source information on the Ancestry record copy and paste into the Zotero 'extra' field. Note you will need to use the Chicago style with notes and bibliography. The record will display like this:
“England & Wales, National Probate Calendar (Index of Wills and Administrations), 1858-1966, 1973-1995 - Ancestry.Com.Au.” Accessed October 20, 2017. Ancestry link. Principal Probate Registry. Calendar of the Grants of Probate and Letters of Administration made in the Probate Registries of the High Court of Justice in England. London, England © Crown copyright.
A minor glitch is that Ancestry.Com.Au is capitalised because it is in a text field and Zotero is interpreting the words as the start of new sentences. A small glitch for a very quick and easy way to add citations to Wikitree.
I haven't tried with other types of Ancestry records yet. I have started a Zotero free space page to show the various ways Zotero can help with organising research and generating citations. It is empty at the moment but I will be working on it as I have time. Any Zotero users who would like to contribute are most welcome.