This site http://www.houseofnames.com/xq/asp.fc/qx/lowndes-family-crest.htm perports to give you an accurate family history, but for Lowndes at least there are many errors and I do not recommend it.
The Arms are incorrect (and frankly odd). The description suggests that the family came to England with the Norman Conquest, but then states that the name Lowndes has an Old English derivation! Such a basic mistake is worth a giggle, but little else.
I’ve yet to find one of these companies that cares enough to get it right (or as right as we can get). I recommend anyone after a ‘crest’ creates one from the freely available images on my site, or employs a professional Heraldic expert.
Lowndes family history 
I forgot to come to a conclusion: The Thrush’s have been around for a long time. We are warriors and martyrs, living in peace, sincerity, generosity, and knowledge.
Not bad encouragement for an Eastern Orthodox Christian.
I had a dream where my mother gave me a gold necklace with a coat of arms pendant. It motivated me to look up heraldry for my father’s and mother’s parents.
Thank you for your page on your family heraldry. It helped me understand her Thrush coat of arms that had “Silver with a red fretwork design, at each joint a bezant”.