Martina 'Marti' Venturi is the youngest MacDonald-Venturi child, excluding Simon. She appears in the show Life with Derek.
Marti appears to be a cute little angel but inside her cuteness hides a mischievous little monster. In the first season to the third season she is small with a short and straight bob hairstyle after that she grows eight years old and looks bigger and taller with two small plaits on each side of her head and speaks with a higher voice.
Marti can be nice, bubbly and funny, but sometimes she may get angry and rude. She loves being the centre of attention, being known as "the cute one". She also acts odd sometimes, like in one episode she was obsessed with purple things, and will only eat food that is purple, and she was pretends to be a cat and in the end of one episode. She was also randomly behaving like a rabbit.
Marti seems to get on well with everyone, but she mostly spends time alone. She's closest to her eldest brother Derek; she calls him "Smerek" while he calls her "Smartie". They seem to have a very close relationship with one another, and Derek behaves like an older brother towards Marti, even going as far as letting her dress him up as a princess. Marti expects everyone to listen to her and entertain her when she calls for it. She tends to get very stubborn if people go against her wishes (despite George getting married to Nora). She also hates people telling her what to do and always has a good comeback (much like Derek) whenever people tell her to do something. She'll result to shouting, screaming, or using her cuteness to change people's minds, which was shown to make Lizzie and Edwin very jealous. However despite wanting to be the centre of attention, she takes sides when necessary, such as teaming up with Lizzie and Edwin to have the same right and allowance, as Casey and Derek or teaming up Derek and Edwin whenever there's a Venturi vs McDonald showdown. However being the youngest, she needs Derek and Edwin to help her with some things in life, but her big brothers are happy to do so.