Albanian independence wasn't declared until 1911, and the country of Albania was not officially independent until 1912. But during the 19th century there were a series of many rebellions aimed against the Ottoman Empire, Serbia, and Montenegro.
In 1878 the Congress of Berlin gave a significant portion of northern Albania to Montenegro and Serbia, after the Russians imposed on the Turks the Treaty of San Stefano in an attempt to give their Slavic Balkan allies access to prosperous seaports. The Battle of Ulqin took place in which Albanian resistance fighters mounted a defense to keep the seaport of Ulqin from going to Montenegro. The "Great Powers of Europe" ended up sending a naval blockade and the Turks themselves had to send numerous battalions to recapture the city and hand it over to Montenegro because they were faced with great pressure from Europe and Russia.
1881 and 1897 see large organized resistance efforts by the League of Prizren intended to defend Albanian land and interests from the Turks.
Near the beginning of the 20th century is when rebellion intensifies and finally culminates into the uprising of 1911, continuing into 1912 when Albanians recaptured cities such as Shkup (Skopje in Macedonia) from the Ottomans, as well as other Albanian cities under Ottoman occupation, prompting the Balkans Slavs to begin a land-grab in the First Balkan War.
While they may not have been an independent nation at the start of your mod's timeframe, they were an independence-minded people under Ottoman captivity that gave the Turks a lot of trouble in that neck of the woods. And during that time Europe was asking itself "the Albanian question," which was what they should do with the Albanians.
I have more information on the situation, as well as battles and maps, if you're interested in adding the Albanians as a minor civilization. Consult with me with whatever questions you have regarding them and I'll do my best to help you out, as well as provide documentary evidence.
Okay, I'll include them. For some reason I thought they gained their independence after 1915, and I was trying to limit vassal states to nations that gained (or regained) their independence by 1915.
It would help if you had a high res image of their 19th century coat of arms, since all minor nations have coat of arms as leaderheads. Otherwise, I'm going to have to use the one on wiki and I don't know how accurate that is.