Der rote Kampfflieger

I think it's possible he had made informal plans to marry after the war -- maybe.

My first line of evidence is based on some his mother's diary, which is one of my favorite sources for learning about his personal life. I can't find my copy of his mother's diary for the life of me right now (dammit!), so the next best I can do without the book is source the Aerodrome forum, with one member saying: "his mother did note in his diary, after the whole "marriage" incident (a mistake the newspapers made), that richthofen did love somebody and wanted to marry her after the war, but his death prevented it. there was no name or anything."

Evidence for a possible marriage plan (or love interest) also can be suggested from his polite behavior towards woman ("Hauptmann Erich von Salzmann, saw him numerous times at his home in Berlin. He observed that Manfred had flawless manners but he was not a ladies man." [x]). However, this could just as easily indicate he was solely dedicated to the war effort and did not have time for any women (or did not want to "widow" anyone should he die). His personality would certainly suggest that.

Apparently the aeronautical history periodical "Over the Front" did a piece on Manfred's love life once, but I don't know what issue. I'm getting this information from this entry on the Aerodrome forum. This entry summarizes the article fairly well though (as far as I know). It draws evidence from the nature of Lothar's (first) marriage, which was arraigned and with a noblewoman. Manfred, being the eldest son, would certainly be expected to uphold similar standards.

The summary of the article also brings up the sketchy testimony of an Austrian girl's family, that was given long after the war, and which the Richthofen family has not recognized as legitimate. 

tl;dr I doubt he had time for a love interest during the war though, nor do most people I've read talk about the subject. However, it is possible he had plans for a (possibly arranged) marriage should he survive the war. 

Flugzeugkennung C.II. In the cockpit, pilots Ihns and Lütjens, and in front from left to right: Döge (?), Freund, Fromm, Christlieb (?), Weth, und Frei. 

Ernst Udet in Aquarellfarben und Tusche über Bleistift auf einheitlichem Papierformat (37 x 50 cm) angefertigt. 

[The following] 32 drawings of aircraft, dating from 1915 - 1941 were made by Ernst Udet in watercolour and drawing ink over pencil on identically sized sheets of paper (37 x 50 cm). Very detailed studies in profile with inscriptions and short notes in block letters handwritten by Udet with the typical spelling mistakes known from his other handwritten documents. The (slightly foxed) paper and colours are more or less identical, suggesting that the fair drawings were made around 1940/41. He signed and dated them after original sketches he largely made during the First World War. The crop marks on each drawing indicate that the drawings were intended for a book project on the development of aeronautics which Udet had in mind, but were not realised due to his suicide in November 1941. 

Udet´s drawing skills are well known from numerous small sketches and caricatures, especially famous are his extremely rare illustrations of captured allied aircraft re-lacquered in German colours - only a few were captured and re-used, and practically none of them survived the First World War - which could only have been observed and documented by experienced front pilots such as Udet. With a comprehensive expert opinion. 

Ernst Udet (1896 - 1941), second most successful fighter pilot of the first World War with 62 confirmed victories, was requested by Manfred Freiherr von Richthofen for the Jasta 11 in March 1918, he received the Pour le Mérite in April 1918 and took over the command of Jasta 4 after Richthofen was killed in action. After the First World War he took up work as an aircraft constructor, actor, and pilot for stunts, shows and advertisements. His close relationship to Göring opened up his career path in the Luftwaffe in 1935, which came to an end on 17.11.1941. At the time of his suicide he was a Director General of Equipment in the rank of a Colonel General. 

Ernst Udet - eleven [twelve?] drawings of German military aircraft of the 1st World War 

Lohner C.I. Bomber of the Austro-Hungarian Flying Corps. 

Albatros B.II. of the Imperial German Flying Corps 1916. 

Albatros D.III. of the Imperial German Flying Corps. 

Albatros D.V. of the Imperial German Flying Corps 1918. 

Fokker D.R.I Albatros B.II. of the Imperial German Flying Corps. 

O.A.W.R.VI. bomber of the Imperial German Flying Corps 1918 (Zeppelin Staaken R.VI. built by the OAW/East German Albatros Plant). 

Junkers J.I. of the Imperial German Flying Corps. 

Hannover C.L.III.a. of the Imperial German Flying Corps 1918. 

Rumpler C.I. bomber of the Imperial German Flying Corps 1915. 

Nieuport 17.C.I. Fighter of the Aviation Militaire Francaise, additional inscription "captured, modified and flown by the Imperial German Flying Corps 1918". 

Camel F.I. of the British Flying Corps 1917, additional inscription "captured, modified and flown by the Imperial German Flying Corps 1917". 

First of all, I'm so sorry for not replying until now. I know you sent this about a million years ago, and probably have since forgotten about it. uughhsdfladsj I'm very sorry. 

Thank you! I have a lot of fun *cough*nerd*cough* searching for and collecting rare photographs, and showing off my finds. I'm actually the only one in my family interested in WWI aviation, or even military history in general, ha. 

eBay Description: "GERMAN WWI WW1 NO SANKE POSTCARD PC RED BARON RICHTHOFEN & TEAM AVIATOR FIGHTER"

Interesting! Though I'm not sure what post you are referring to, so I'm not sure which "official" version you mean.