
Despite the heartbreaking imagery and flavor text, Abandoned and Alone is not that critical a weakness like some of the others are. Yes, taking two DIRECT horror could be game-ending, but knowing that this is in your deck, you basically make plans to ensure you have that two horror buffer (and with Wendy's starting Sanity of 7, this should not be TOO hard). Of course, sometimes you just have to take all that horror, which results in you being scared of being defeated by drawing Abandoned and Alone.
Abandoned and Alone removing all of your cards from your discard pile can range from inconsequential to devastating; the primary determination of which is whether or not you were planning to play Wendy's Amulet, or if you had something to pull out with Scavenging. Scenarios in Arkham Horror are generally so time-limited that you rarely draw through the entirety of your deck; making the reduced number of cards in your deck when you reshuffle a non-issue. As more investigator cards come out, we may see cards that interact with the discard pile, which may be an issue for Wendy decks.
There are not many solutions to the discard problem, but there are solutions to deal with the Horror aspect. Probably the best solution in the current Dunwich Legacy cardpool is to have Wendy put out her best ally buddy, Peter Sylvestre, to help deal with other sources of Horror (to ensure she has the buffer needed to take that direct damage). If Wendy has other allies she'd like to have (Leo De Luca and Cat Burglar to name a few) without investing in the additional ally slots that Charisma has to offer, then she could instead use a Smoking Pipe to help convert that excess horror away.